I did a DIY short shifter on 2 9000s by now (mine and another member's '95 Aero). On the 9000 it's easier, as you don't have to cut and rebolt the aluminium box, because there's none. It's enough to put 4 stack of washers under under the sphere housing. I spent exactly 0€ to do both, The only expense would be 36 6mm washers per car but I had them lying around so I spent nothing for them.
I found that 12-13mm (half an inch) were enough to shorten the shifter, obviously the levers on a 900 are different. Raising the mounting isn't just to leave the knob at the same height than before, it's to allow clearance for the rods against the car's floor.
Other plus, on a 9000 the procedure is reversible, when you sell the car you can remove the mod. The only thing that needs to be sawed is the collar for reverse protection, but I got one in a junkyard and cut that.
I'm not saying that I invented this procedure for the 9000, actually, I got inspiration from some people on TSN (Chad and AJagodnik). I'm saying this just because I noticed that nobody has mentioned a DIY short shifter for a 9000 on Saabscene before me.