Measure where the shifter will end up on your truck, alot of them are too far back and end up in the middle of the seat. You can get a mid-shift relocation kit for a bit more.
The LT (94-97 fbody) version of the T56 is easiest, but depends if you want to retain the stock mechanical clutch linkage. The LSx versions can use an adaptor plate to work with a older muncie-style bell/clutch/etc.
If you're looking for new, you might want to look at the MagnumT56, since it offers various shifter options and other retro-fit features. (mechanical speedo, etc.)
If you throw back some additional requirements, we can narrow down the choices.