from my research a few months ago: manufacturers that offer rear shocks for our bikes ... all with adjustable preload and choice of spring rate
entry-level 3-400 for a progressive or YSS
+1: generally w/ adjustable rebound: ohlins, penske, hyperpro, works performance 6-700
+2: add adjustable compression: penske, works performance, 850-950
+3: add hi/lo compression: penske, racetech, elka 1100-1300
I forget where the bitubo fell...
Me, I picked up a used penske w/ all the adjustments (incl. hi/lo compression and remote reservoire) and - while being very happy with it - feel that for the street that last feature (takes you up a price level) simply isn't worth it.
Remember that due to the angle, an inch of adjustability will have less effect on ride height that you'd imagine at first. But if you want to 'tweak' the geometry a bit, and have the oversprung forks in the front, you may want to try giving it a bit more sag (though you really should get the correct springs for your weight ... it will make a noticeable difference and balance out the improved rear)
If you want to simply add height ... perhaps a seat job?
If you're looking for more clearance ... keep your eyes out for a great deal on a versys?
I know I've been tempted...