Just make sure it's a decent make and not some cheap Chinese bull! If at 88,000 points at engine mileage, that's nothing on a K20. They're built pretty well if looked after.
Before doing a boost upgrade, i'd get a good service, including valve gaps, full fluids change, check the tensioner for the chain etc. Make sure the engine is as good as it can be before going any further.
Once that's complete, get to sorting the cooling properly. Bigger rad, oil cooler, better hoses. Anything you can do to keep the extra heat down.
After that you'll want supporting mods eg. Air Intake, exhaust manifold, intake manifold, bigger throttle body etc. And to keep this lot in check, you'll want a good ECU. KPro, Syvecs or Link are the usuals for turbo applications.
Once this is all sorted, then you can start looking at turbo's etc. If you want max power out of it, you'll want to look at a fully built engine with better lifters, pistons, rods, cams.
Basically, if you're going cheap, then be prepared to build the engine repeatedly. If you're going full on, good turbo, good supporting mods, then expect to have deep pockets.
Tom on here is one of the guys i'd be talking to. He had an animal of a boosted EP3.