727 Build Suggestions

If you value your feet and legs you want a billet front drum and a bolt in sprag (preferably the 16 roller)
Other than that possibly a Kevlar solid front band, billet rear servo, bronze pump bushing and a front seal retainer.
Good quality rebuild parts made for performance Like Alto or kolene clutch discs.
Possibly the 6 gear planetary gear assembly as well.

If you want real firm shifts you want the higher performance options of the shift kit done and possibly even a new governor calibrated for higher RPM shifts, and a blocked or well sprung accumulator which should also be billet and have D rings on it.

Tracy may have more to add, as he builds 727's.