I stay away from flywheels, I'll leave that to you and your engine builder. I have seen the damage from an OEM flywheel; it went off like a bomb and opened up the bottom of a 55 chevy like a P-38 can opener, the drivers door had a chunk of flywheel inside it if I remember correctly.
If you go to an large clutch (11") you'll need a new front bearing retainer (snout) for the transmission. They're not spendy and are made from the same casting as the standard diameter ones.
I prefer a cast bellhousing (iron is fine in this case) for street rods, it usually eliminates the need for the offset dowels, or Quicktime if you have to have a scattershield. the offset dowelpins can be a pain in the butt, but are sometimes necessary along with a dial indicator. If you have to 'dial it in', as little run out as possible is preferred. RobbMc makes some pretty trick offset dowels, but I have very little personal experience with them
For a mild street clutch, we have had good luck with Luk Rep Sets and McLeod dual frictions. I had an awful personal experience with a Centerforce that involved having problems with those wired on weights....never again; but lots of other guys have positive experiences with them