Ok, basically you are getting an entire donor car? I am assuming so, so here goes.
Take the engine, transmission, ECU, wiring harness is optional. The mounts might be handy to. you will also need the axels, but you need to get those out of a 3rd gen, I don't think a 90-93 will work. The swap itself is extremely easy, basically you can drop it straight in with a combination of the teggy and civic mounts, everything will bolt right up and plug right in. I am also assuming you already have a manual transmission setup. The only thing you are going to have to buy, as I said were the axels from a 94-01 teggy, but those are easy to get at just about any Wrecking Yard in your area. I think i got all the bases covered here... you might want to look into the rear disc and larger front disc conversion you can do with those Integras. I am not sure if the 2nd gen that you are getting can swap in rear discs, you might have to search that out.