I was considering doing the same swap at one point, but now I'm going another direction. The 94 cross member should work on the 95. I have a 94 cross member and have been told by a few knowledgeable folks that is will swap over no problems.
I don't think you can get your stock harness to work. Like john said, you should just swap over the harness and ecu, etc. It's nice you have a donor vehicle so you can also swap over the boost control solenoid and other bits, unless you are going with a mbc. If you don't use the stock boost control solenoid you will get a cel. You can get around this by finding this funky little part on non turbo first gens that is bolted in the same place as the stock boost control solenoid. I read all about it on legacycentralbbs. You might also have to swap fuel pumps.
How far are you tearing down the engine? Are you splitting the block? If so you might want to replace the main and rod bearings, but that is going to cost you a couple hundred bucks and will cut into your budget. I split the block on my 22T w/160k and the bearings looked brand new, but you won't know the condition of yours unless you take a look. They are probably fine though. Also, the oil squirters may have come loose and fallen out. One fell out of mine. You should at least remove the pistons so you can check.
I would definitely change the headgaskets. They are prone to fail like the 2.5s. I know this from personal experience when my SS HGs failed. When I pulled the motor I replaced every seal I could get my hands on, including the rear main seal. The rear main seal doesn't really need to be replaced if it is just barely weeping, but I did any way. Definitely replace the oil separator plate. It's easy to do and only about $33 bucks for the kit. Timing, water pump, pulleys, cam seals, camshaft support o rings should should be replaced. Reseal your oil pump and check the screws in case they have come loose. Good time to reseal the oil pan if it is leaking.
Replace all the vacuum lines, PCV lines, and coolant hoses, otherwise you may be chasing boost leaks and coolant leaks for a while. Some of the coolant hoses are a bitch to replace once you get the motor back in the engine bay. I skimped on a few coolant hoses when I pulled my motor and it sure sucked to replace them later when they failed.
The purge control solenoid valve is most likely bad. A new one is $120. You can try to pull one from a junkyard vehicle. It's the same for the 22E as the 22T. I pulled a few from the junkyard and they were all bad so I finally bought a new one from the dealer. The car will supposedly run fine with a bad purge valve, but you will have the CEL which is really annoying. Also, relocate the purge valve to the top of the engine. The stock location is a really bad spot to access it, and requires removing the turbo and intake to reach it. Simply reroute the vacuum lines and use the existing bolt on top of the intake mani to bolt it down.
You will also need to use the exhaust manifold, up pipe as well as the down pipe. I'm sure you know this already. Replacing the gaskets for all of these pipes is warranted. The donut gasket that connects the downpipe to the midpipe is probably shot too. It needs to be for the 22T. The 22E donut will not work, it's too small.
The turbo inlet elbow on the 22T is no longer produced by Subaru. Be VERY careful when you remove it. It will crack if you look at it sideways.
That's all I can think of right now.