my advise is, if you a worried about the age of the engine etc, is spend more on the purchase eg find one with a fresh engine and new turbos, sure you might have to spend 5k more initially, but saves you worrying about breaking stuff.
But on the other hand stay away from ones claiming to have 100k spent on them very recently then all of a sudden up for sale for 20k.
Find one with the basics done, fresh turbos, fresh engine & pfc or similar (built by a good builder) and talk to the workshop that did the work and be prepared to look at upwards of 10 cars until you find the perfect one for you.
Im in the same boat as you, looking to grab one next year