I am purchasing a 1995 Impreza AWD L, with the 1.8L engine (5Spd). I have done a bit of research and it seems like I can swap 1 of 4 engines into it.

an EJ20, an EJ22, an EJ25 and a WRX engine. Now the WRX I assume is a different engine than the EJs. This is the first car I feel really passionate about, and the first car I am planning to do work on, and I was wondering which engine is a reccomended swap, from where (I heard that the EJ25 Turbos from the new Legacy are good if it's possible to do that) and what else would I have to do to accomodate the swap? Would I need a new transfer case? How about suspension and brakes? Or transmission? I read somewhere that I might need a Hood with a scoop if I do the swap. Does the OEM 2.5RS Style Hood just bolt on where the L one did?

I hate when people simply say to do a search, but you've got so many questions there that have all been answered many times over on this forum.

Basically any engine subaru currently makes can be swapped into your 1995 impreza. Some requiring more work than others, but none requiring any major fabrication other than the wiring harness.

You're asking some very basic questions which makes me think you'd benefit a lot from just reading through some old threads here before attempting a swap.

So do a search, newb. ;) j/k, sort of.

I ran a search, but I foolishly did it under the wrong parameters (searched under model rather than just engine swap) So I can swap anything I want INTO it, but would I require a new tranny for some of the trickier swaps?

Legarus. And all of the above are EJ series engines. An Ej20 is a WRX engine...

You can run off the L tranny if you want, wouldn't be the most durable thing though, and the stock clutch would probably be good for 3 or 4 second 60' times at the drag strip. EJ series engines can bolt up to any other ej series tranny, the clutch, pressure plate and flywheel have to match the tranny.

Subarus are like legos, but anything you want together.

WRX motor is an EJ205
JDM sti motor is EJ207
USDM legacy/sti is EJ257

Depending on your budget I would get one of these motors, because turbocharging is the way to go :) Keep in mind the most difficult part is wiring for you car, no matter what engine you choose, they will be equally hard (although the USDM sti motor is even harder than the others)

I would recommend a WRX motor or a JDM sti motor, whatever version you want.

Your stock transmission can bolt up to any motor you choose, but it will probably only handle the power from a WRX motor, I don't know if I would trust it with the higher output JDM motors. If you have the cash, you can get the matching more beefier transmission.

Check out Kingpin, IAPerformance, and Gruppe-S for JDM version 7 motor and transmissions (and WRX motors/trannys), and gr8wheels for JDM sti version 1-6 motors/transmissions.