Cross Member - Specific to the T56. The 03/04 Cobra piece will work in a 99/04 car. For a 96/98, you will need a non-OEM piece.
Trans - Any 4.6/5.4 T56 will work. The F-Body stuff is difference
Clutch - If your clutch is 10spline and the T56 is 10spline, you are good to go.
Reverse Lockout - Either take it off the trans (kinda dangerous), muscle it into reverse, or put it on a switch
Driveshaft - A T45 is 31spline and most T56s are 27spline. The T56 is also a different length from T45s and 4R70Ws.