The TII tranny and driveshaft are worth some money along with the engine of course. You won't need any engine brackets, it is easier to use the accessories from the new engine. You will need some of the wiring harness, don't cut anything yet!!! The TurboII engine harness is worth a little money if it is in good shape. It can be removed while still retaining the wires that you will need.
Spend plenty of time searching on V8RX7.com and don't piss off the rotary fans, they can be very helpful and they may be interested in some of the parts you will not need.
Edit, Here is a page that describes the wire splicing if swapping an LS1, it's still useful if going with something other than LS1