Do your homework and try and limit yourself to buying only one pair of shocks.
If you are going to ride two up a lot you may as well get the stock height replacements when you do it. besides the extra inch of ground clearance you have an extra inch of shock travel. That will be an improvement with whatever you go with.
Your main problem is the factory air shocks = garbage. I was ready to sell my bike (05 SEEG) until I tried the progressives.
My take (based on personal experience)
Progressive's - night and day improvement of stock, and the reason I kept the bike. For me (160 pounds) the Progressive standards were fine, including when my wife was on (and I'm not going there).
The progressives worked fine for a couple of years until all the hoopla with the Traxxion - Bitubo hype.
You will get an annoying "stop bump" with the Progressives (as the suspension unloads going over bumps).
If you go Progressives you should seek out the recommendations for your riding weight as to the stock or heavy duty version.
Progressive preload can be adjust by popping the bag pins out and moving the bags away a bit. Hands only to adjust (at the top).
Bitubo's - expensive and have a learning curve. These shocks have three adjustments, which are sequential, ride height-preload, compression and rebound damping. Preload is first, don't remember about the other two.
Nice shocks, expensive, have to be aware of mounting position so they don't hit the bags. Adjustment requires removing the saddlebag and using a wrench (supplied, bottom of shock). Some coat the "screw" with some product which escapes me at the moment and claim that the shocks can be adjusted by hand. I am leery of any lubricant on the threads (dirt collector).
I ride from 1 up, no tourpak, empty saddlebags to 2 up, king tourpak and saddlebags packed as well as a bag on top of the tourpak and everywhere in between. So the adjustments on the Bitubo's were a pain in the butt.
Next up
Arnott air suspension with the upgraded shocks. These were nice, solved the problem with the load capacity with the infinite adjustability. Problem for me was two fold. Since I didn't install a pressure gauge I was always searching for the best ride after making a change. Pressure gauge would have given me a number to go by.
And since the majority of my riding is solo the ride quality was kind of harsh.
The minimum amount of air to keep from bottoming out gave a harsh ride. When the bike was loaded though it did seem to ride pretty good. Air shocks (at least the none 2 chamber systems) seem to work better when the rider approaches the 250 weight mark.
Last month I pulled the air shocks off, just wasn't happy with them.
Put the Progressives back on, rode for a week and pulled them. The Bitubos are now on the bike. And except for the preload changes I probably will not screw around with the other two (compression and rebound).
Traxxion front cartridges. Lot of hype here with this setup.
I think it is more of a mindset after the spending the coins that these do what they do. Granted I have seen an improvement but I don't know about a $1200-$1400 dollar improvement.
I did increase the travel to stock height, so that is a plus, the system is a better design over stock, another plus (1 cartridge versus 2) and you are rebuilding the forks with this upgrade.
Honestly though, the only improvement I can really feel is pulling into my driveway. And this may be indicative as to how the forks perform overall.
I have about a 2 inch bump into my driveway (street was never top coated with asphalt). With my old forks I used to slow down almost to a stop when hitting the driveway or it was a very harsh transition.
Now I just pull in at whatever speed I am moving at and all is fine.
Something else to consider with the higher end option here. Both the Bitubo's and the Traxxion upgrades both recommend yearly or 25000 mile overhauls.