Welcome to the board! As for mileage, it kind of depends on how the car was maintained, but these cars are fairly reliable with pretty good engine life. My 2000 RS has 81k miles on it, turbo kit has been on for the last 30k, and I did 3 seasons of rally-cross with it earlier in it's life, and it's given me zero problems besides normal wear-and-tear stuff. And I bought the car new in Summer '00, it's been a great car. When you go to look at one, look for oil in the coolant or coolant in the oil, and also watch for smoke coming out of the tailpipe on the test drive, all signs of a possible headgasket problem, probably one of the more common problems on these cars, at least if it has the stock EJ25 engine in it. Now, if you are going to be doing a swap yourself, maybe look into getting an Impreza L AWD, as they are cheaper than the RS and have the same chassis, so once you swap engines, it's just cosmetic stuff that would be different, like the front bumper and interior color. Just some food for thought, and good luck with the hunt!