Get a V3, its the same year/generation as your current car and will produce *much* less headaches when it comes time to do the swap. Spend the extra coin and get a half cut, one that includes the rear drivetrain as updating to a V3 sti box will mean different ratios. Being a V3 sti it should also come with 4 pots if you get the whole cut. Then you can sell off any bits you don't want to make some money back. V3 dash & cluster etc.
V2/V3/V4 are all a bit of bastard years where not a huge amount is interchangeable between them without doing a lot of work. A same year swap can be done in a weekend, dicking around with different things can take much, much longer. My car runs a V2 sti body loom with 06 legacy motor and engine loom, 08 sti
ecu, v4 dash and cluster. Lots of custom work means lots of $$ and time.
As long as the proper servicing has been carried out on the motor, even one with 250,000km should still be pretty good. Your mate probably keeps busting motors because he runs more boost on a stock
ecu and sits on the limiter like most drifters.
While you have the motor out, you may as well do a "100k" service, ie belts, pulleys, water and oil pump etc. while this might cost you another $1k on top of everything else, then you will know for sure you have a quick, reliable car for years to come.
If you are looking for a cheaper fix, the guys at STechnic (DTrally) can probably fit an early liberty motor and either rebuild your box or supply one in better condition than your current box