what i personally would do depending on how much power you putting out, would be 1st check the current reverse input drum and make sure its absolutely flat, if so, i wouldnt worry about the drum.
other than that, id get the dual cage sprag, the z-pack 3-4 clutches, (personal preference after learning a few things from the old man), and depending on if ur going to be running the engine above 5500 WOT the hardened steel rings for 5500 and above, and finally the trans-go separator plate (just to be safe unless you already know that the separator plate in the trans is ok).
the choice of conveter is up to you with the consideration of what youve done to the engine, if its basically stock, then a good rebuilt aftermarket converter from anywhere like WITtrans or a hughes, or as you mentioned should be fine for street use.
only thing i noticed otherwise is the application your putting it in.. that too is important... 1 other thing i might suggest is to go with a corvette servo if you dont already have 1... and get the atsg manual to help you along the way...
these transmissions have a common 2-3 flair issue after rebuild, but if you follow everything closely, you should be ok... best of luck on your first 700R4 rebuild... there a good trans.
p.s. dont forget to add "the beast" sun shell if this kit dont come with it. another weak link in the 700R4...
and im sure there other things others will mention that i didnt, but then again, id say its going to depend on how much you want to spend... lol