That rebuild kit looks fine. I would suggest a valve body reprograming kit (shift kit). It ungrades the transmission internal pressures and shift timing to eliminate soft factory calibrated shifts, reduce slippage and heat build up.
A Transgo Shift kit
shift kit is about the best on the market. The "B&M transpak"
is very good also. Do the 'stage 2" set up, not the full race version. The full race install version is full line pressure bang shifts all the time. its a little too much for the street. The stage 2 hi perf street/strip set up is plenty. Allows hard shifts at WOT yet reasonable at part throttle with increased up and down shift control. Really wakes up the tranny while increasing reliability. both these brands of shift kits retain the auto shift in Drive yet allow full control over manual shift thu the gears for racing.
retains the vacuum modulator for smooth part throttle shifts in "D"
If you want a functional "kick down" "passing gear" for passing in "D" (auto downshift) retain and hook up the kickdown cable to the carb.
I would use a 11" "3000 stall" th-350 converter. You're going to need some sticky tires to get traction. Get a inline auxillary tranny cooler. The B&M cooler is good.