ive bought engines in the past from http://attarco.com/

they have pretty good prices and their engines have been top notch.... I'd recommend them.

As for install work, I dunno. I had just done the work in the past with buddies of mine... Good luck though!

 

Pick n Pull or a private party selling a wrecked vehicle with an illegally swapped SR20 engine in it (only way you can get it here in the states, yes) would be cheap. But quite frankly, the cheapest way to get an SR20 powered vehicle is to buy a 240 where the owner has already performed the swap (and probably did a whole bunch of other changes to the car). But it's a crapshoot considering the abuse these cars see as track vehicles or worse, street-driven "race cars."