Back in my poor days I had an AE90 Corolla in which the 6AFC expired. A mate had put a 4AGZE into his AE92, so I bought from him the complete 4AFE that came factory in his car. Be very careful to ensure that you get everything you need with the engine - I recommend strongly getting a half cut. Also make sure you get one from the same model of car as it will bolt in a bit easier (often bolt holes and brackets are the same between engines).
You're on the right track though. There's lots of labour involved but it's pretty straightforward. I'd budget for new wheel bearings and probably look at a brake upgrade.
Then sit down and work out if 20hp or half a second off your quarter mile time is really worth $4000. Personally I fitted a $25 bleed valve and a $900 exhaust to my turbo car and knocked 2 seconds off my quarter mile time.
Maybe look at selling your car and combining the funds with said $4k to get something factory turbo that has an easy upgrade path?