For the ultimate in Luggage, there is no question.  GIVI makes the best, if not most expensive luggage.  Visit their website for information on available styles.  GIVI used to be solely distributed ion the USA by a company in North Carolina.  This company (Capitol Cycle?  You know who you are!)   consisted of con-artists and generally undesirable business people with no clue on how to distribute items or treat its customers.  They have earned a place on my blacklist. 
    There is a new distributor (Thanks! I wonder why??) and I have not dealt with them.  I picked up my luggage on a business trip to Israel, due to Capitol Cycles failure to deliver.  I currently own the Maxia 50 Liter bags, and I think that these bags are the largest motorcycle bags available.  Correct me if I'm wrong.
   To the right is the Magna with the two sidecases loaded.  Mounting them is not an easy task.  First, you will probably want the wingrack, with the integral turnsignals.  I can't think of any other way to mount them.  Givi makes a universal mounting kit to mount the wingrack, but IMO this is really not that desirable.   It is indeed universal, and you can mount the bags, however, the mount is very shaky due to a combination of the mounts, locations, and the Magnas frame in that area.

Mounting the Wingrack on the Magna
As mentioned above, the universal mount available through Givi is not desirable for the Magna.  I have used it with success, but was not happy with the results.   Then how do we get a reliable mount?
    First of all, I have the wingrack on the Magna, with the signals and the top mount piece.   As an interim solution, I made rack supports out of aluminum strips, I think 1" by 1/8" thick or so. This works out a lot better, since there are few good mounting points. The key is to get a solid mount to the rear under seat bolt, and brace it with a piece that attaches to the front shock bolt. A cross rod at the back of the wingrack helps out a lot too. The footpeg mount is so far away that it becomes almost useless for support.
    This way is also a little shaky. This is because of the way the frame is at the very end. It has a flat section, and some very weak supports from the front of the seat back. The mounts go into different sides of the frame that are not connected anywhere close, and you have to come down 2 to 5" with a strip just to connect to the bolt. This produces rotational stresses that the frame does not handle well, as evidenced by the tendency of the bags to ‘wobble’.  Once they are mounted, you will see that the whole rear of the bike tends to shift with the luggage.
    I have developed a new way to mount them, however. It goes hand in hand with frame-strengthening.  The key is to put some sort of support (maybe a threaded rod) between the two mounting points on the frame. This would imply drilling out the aluminum rails to facilitate this. When the racks are off, you can just put an acorn nut on the end, when the rack is on, these can be used as mounting points. This is still in development, and the measurements that I’ve made so far show that the rear tire (150-80, radial of course!)  will not rub when bottomed out, but a piece of teflon across the rod would provide some insurance.
    What I’m doing is having a rod made, out of steel, and having ‘bolts’ brazed into the ends. This will allow a standard bolt to be used, an acorn, chromed one for no rack, and a non slip one for the ones with a rack.  This rod is part of a general frame strengthening procedure that I’m working on. This rod will provide support for the luggage, as well as strengthen the frame in the passenger area. I am strengthening the whole frame, to stiffen it and accommodate the additional HP I will gain from DD’s ported/polished heads and radical street cam. Also I plan to eventually have a dog-trailer, to haul around two Pschyo Killer (Not my name for them, I think they are very tame)  German Shepherds!
    The photos below illustrate the mounting.  In the far left photo, note the only real place to mount the rear of the rack  (white arrow).  This is accesses under the grabrail from the inside with the use of an 8mm bolt.   Also look at the cross support of the frame in that area.  Not much!  This is where I will eventually insert a brace to bolt across.  Further details on that will follow at a later time!  The middle and right hand  photo show how I am currently mounting the rack.  Notice the required 'spacers' in the center photo.  This puts quite the 'torque' on the rear of the frame, but there is no way around that yet.   Also note that I had to come 'down' off of the bolt to the frame, about 2 to 5" to clear the frame and the grab-rail.  This also adds to the instability.   There are two solid side braces to the shock mount, which is about the sturdiest place this is mounted.  I find that using the passenger footpeg is next to useless due to the roundabout way that the braces must go in order to clear the shock.  In the center photograph, you will notice a threaded rod towards the rear of the rack.   This is not what I am connecting to the frame.  This piece was used previously to connect the 'tail end' of the wingrack together.  There are mounting holes that allow you to do this.  I found that without this rod, the bags had a much larger tendency to go their own way independent of each other.  As it sits, the threaded rod is too short at the moment.  This was used on an earlier incantation of the mounting scheme.   I included it for reference, since if I use this mounting system again, it will be a welcome addition.

Related Links
Givi Home Page
Givi Information

FAQ!
Can I get extra lock cylinders if the keys do not match?
Yes.  The lock cylinders are reasonably priced.  To quote Givi: The lock set you will need is Z228 $14.00 suggested retail price, I would think the best place to order these items would be at Road Rider, San Jose, CA Phone # 800-331-6644 ask for Dave or Bill, they can drop ship these directly to your home address.