hi mate welcome to the forum, im new as well looking to buy one hopefully soon, been to see a few but not found the right one yet. Things to look out for is like white/blue smoke that show signs of turbo on its way out, do a compression test so take one with you, check for oil leaks, seals and cracks around manifold and the head, check for rust etc. Usual checks you do when looking at a car. Also make sure car has some sort of service history that's quite important.