del sol/auto ex dual core is fine - $100 at any parts store (cheaper on ebay)

Exhaust is chassis specific, not engine. Header, singular. Not headerS, plural - you have 1 set--and it needs to be for LS. If youre going turbo, just get a used oem for cheap. Also, for turbo, you will want something minimum of 2.5" exhaust diameter.

the shifter is fine

ecu p75 obd1 or 2, depending on whether you want to use a jumper harness or not


That price to me, seems like a giant rip off...but thats because i paid $200 for my ls longblock. If you get an engine from a junkyard, it will be cheaper.