WRX Swapped OBW Planning

I hope this is the right place to ask my questions! I'm planning an engine swap for my 01 OBW. I have a hand full of questions I hope someone with experience can answer.
First question is: which engine? I was originally going to use an ej205 from an earlier wrx... (Definitely easier/cheaper to find) Friend convinced me to shoot for an ej255. So my question is what would be the best year to get the motor from? (Was thinking 2006?)
Second question is: I know all the bits and pieces will bolt on from the ej205 but does anyone know from experience if the ej255 bolts in just as well?
Third question is: what's my best option for the swap? I'm assuming that I should find a totaled or r title WRX for the swap with all the components and wiring in tact especially because I will also need the drivetrain. (This is probably the best option people will suggest but just looking for confirmation lol.)
Fourth question is: what supporting mods should I plan on? Hopefully the engine I find will be in good condition so well just assume I've done that. What humble power level (280-325 chp) supporting mods should I do while I have the engine out the first time? I'm trying to get a price list together also so I'd like to factor those in.
Fifth and last question is: does anyone have any recommendations to threads that have helped them a lot? I'm always reading through forums but there's always some hidden gems you won't find just browsing.
I know I'll have wiring woes later on but I am going to college for electrical engineering so I like to think I'm good at wiring.I hope some of my questions can be answered here, thanks in advance!
(Damn what a long first post.)

1: I'd highly recommend reconsidering the EJ205 or JDM EJ205 Variant, Stronger out of the box and cheaper. but anything pre canbus. 04-05 FXT?, 03-06 Baja?, and 06-07 WRX, and GD STI's.

2: Pretty much same stuff as a 205 swap, other than maybe a DBW Gas pedal bracket. Any EJ, EG, and EZ will bolt to any EJ Transmission.

3: I did my 205 swap piecing everything together If you don't really have space or motivation to part out a car, I wouldn't bother. just find a good engine, and start collecting the parts to do the swap. but buying a cheaper wrecked car makes more sense if you've got the space and time.

4: first do Stuff like Shifter bushings, transmission mounts, etc.. it's way easier now then later. and engine wise, pick your long-term and start to prep the car for it. most of stuff can be done in the car so I would just focus on getting it swapped.

5: This is a good read https://sl-i.net/FORUM/showthread.ph...uple-questions