There are to many options, but this is the basic saleen:
-Aero kit - rear wing and ground effects
-SVO/Lincoln mark7 brakes, 5 lug. 10.8" front with 73mm calipers, 11.375" rear with 54mm calipers. Rear end is 1.25" wider than stock.
-usually stickers galore
-hurst shifter
-saleen gauges
-optional flofit or recaro seating
-SVO master cylinder
-Racecraft suspension -- shocks, struts, quads.
-Saleen springs
-3.55 gears
-5 lug 5 spoke wheels, special offset for the rear 16x7 front, 16x8 rear for '89
From there, you have ones like the SSC and SC units and then the SA10s in the later years. Then you have the hatch, coupe, and verts. They were all built off the LX cars originally. All have various engine options that could be added by the customer or dealer. The basic saleen was stock with a borla exhaust. So HP was 225hp. The 90 SSC had a cam, head and intake porting. Some exhaust and TB/MAF mods. The 90-93 SCs usually were supercharged, but not all. They can have the Holley like EFI intake and 87MM ProM. The 93 SA10 was a serious car, but only like 9 were built, 8 survive. Something about 500hp in them.
http://www.performanceautosport.com has a ton of them for sale.