Well personally, I would think the higher mileage car with a rebuilt engine would be in better shape(generally). The extra 15k wouldn't make that much of a difference and at least the engine is new. The upgraded parts could show that he drives hard, but also that he takes car of it in upgrading. You really just need to check it out fully. as far as the 3rd gear synchro, you can get that for a few hundred, but if you are getting someone else to repair it, it will probably go over a grand to replace. The exhaust...you'll need a new catback. but the good news is that alot of people sell their vr4 catbacks when they upgrade to aftermarket exhaust. So, you could probably get that pretty cheap 75-200 on
www.3si.org. Once again, depends on if you do the work or not, but if you sell the exhaust that is on there, I am sure that would help. Muffler companies might charge a hundred or so to mount/dismount exhaust. To me it seems from the pics and parts he has that he was pretty safe with modifying and that he took pretty good care of it. For example...his boost is set at 13, not 14.5(so he's not squeezing out every possible psi possible) But then again, you can't judge how well he drove the car. I really don't know...if you want to check out that other car, then it might be a good idea, just to compare the two, even if you don't buy the one that is 180miles away. I drove about 195miles to look at the vr4 that is now sitting in my driveway, so it might be worth it. All in all, just check the car(s) out thoroughly, find out why they are selling them, and use your good judgement. When I got my vr4, I even had the seller sign a letter saying that the car was in good condition and didn't have any serious problems to his knowledge....that type of thing. Just as an extra percaution.
All in all, there are 3000gts on this forum that have well over 200k with rebuilt engines, tranny. So the car can last, if you take care of it.