why dont you just buy a Turbo baja. they come factory turboed. if you want sti power out of it, then buy a downpipe, full 3" exhaust, and a access port and get a good tuned map. you should be damn close to STi power. even converting to a td04 would be a good improvment over the vf40. but a vf39 you would be set.
other wise, if you insist on swaping, its a bolt in swap. and very easy to do. (to me anyways)
motor swaps would cost you 4k even. Plus other parts that are always needed (small things)
and then if you had to do labor as well.. well count on 90 bucks an hour and a 40 hour minimum. wayy to much money would not be worth it at all.
then you can add in another 5k plus more parts and more labor if you wanted to convert to a STi 6spd tranny. and thats only if the axles work. you might have to do a axle and hubs swap. which means you have to do a brake swap as well. So theres anotehr 3 grand out the window. and with the brake swap requires STi wheels, or wheels with the same specs as STi wheels. so theres another 1000 bucks minimum out the door in new wheels and tires.
I just bought my turbo baja 2 days ago... got it for 14,900. has 50k miles on it. and of course its turboed. factory pushes 210 hp. on the small little vf40 turbo.
Convert to a vf39 (500 bucks)
Bigger injectors (150 bucks)
Fuel pump (20-100 bucks)
Down pipe (100 bucks)
Up pipe (100 bucks)
Cab back exhaust (500ish bucks)
Larger intercooler (200 bucks)
access port (600 bucks)
Solid dyno tune (250 bucks)
and your going to be pushing a conciderable ammount more horsepower than a stock STi... and thats only 2400 bucks out the window.