iVerticaL

Hey guys, I'm brand new to the forums, as well as the S-Chassis community as I barely acquired my 91 240sx. I had the KA24 in the car and it had a blown head gasket, fixed it and well other issues came up that I didn't want to deal with since I already knew I was going to either LS swap it or SR. Ultimately going SR as a friend of mine is giving me a steal on his redtop.

I come to the forums because I guess my questions are less on the "Complete Swap" side as I'd like to budget this as MUCH as possible and I'm fairly new to this chassis (I drive a 17 Camaro SS)

My first question is, if I'd like to keep my current KA trans, would I just need to replace the bell housing? Also, would the stock ka fuel pump work for a stock sr?
Any recommendations on where to buy a ecu/harness or should I just go on offerup/craigslist to grab one?
Battery is already relocated to the rear of the car by the way. Can my current radiator be used on the SR?

Parts I BELIEVE I need (please correct me)
- ECU
- HARNESS
- DOWNPIPE
- SR BELL HOUSING
- FUEL PUMP (maybe?)
- BOV

Would really appreciate your guys' help with this. Again, if this has been asked before, please forgive me, as I'm new to this chassis/page! THANKS A LOT.

Edit: I still have the KA/Trans so any parts I can pull from the engine to complete the swap (if need be) please let me know.