Hi Nick, mind if I ramble a bit?
PPI: I have never paid for a PPI. I have bought over a dozen 986s - most (but not all) of which were running cars. I have replaced IMS bearings, brake boosters, window regulators, coolant tanks, and a few air-oil separators. I know that there are still things that I will miss or overlook when I go to buy a Boxster. For me, that's okay. I'm paying with cash and I fix them for recreation. If I was financing a car (20+ year old sports car) and did not have the reserve to repair it in a worst case scenario,
I would gladly pay a reputable Porsche shop to do a PPI. At least print up a good checklist and bring someone along whose only job is to talk you out of the purchase.
By the time they reach this age, the condition of a 986 can vary widely not just based on mileage and year, but by how it was cared for. It is possible that a 180k mile 1998 is in better condition than a 2003 with 90k miles on it. If you are buying from a typical used car dealer, there will probably not be much detailed history of how the car was cared for. If you buy from an individual that was an 'enthusiast', you may hear more details and stories than you want. Consider arranging your financing before finding the right car from a place like
https://www.penfed.org/auto/ . That may open up your market to a wider range of cars.
You mention that you are willing to do some wrenching on the car. That's good. Replacing an item such as a water pump may cost $1,000 at a dealership. You can do it yourself for under $200. ...but also consider that you could do it incorrectly and end up needing to have your car towed to a shop to be done right. Learn on the easy jobs before you take on more complicated ones. Know that you will need tools, a place to work, and some knowledge. These cars are not particularly hard to work on, but they are different from your typical Hyundai or Ford.
The IMS bearing problem is exaggerated. ..and it is very real. There is no magic number of miles that means yours will never fail. Consider it to be a maintenance item to be replaced with the clutch, or get an 'IMS solution' and be done with it. There are still plenty of things that will kill an engine - broken rod bolts, head cracks, water pump failure.... Maintenance is important, but sometimes any 20 year old car will decide to fail. Don't expect it, but know that it's a possibility.
Everything that you need to know has probably been discussed at least a few times on this forum and others. In most cases you can find contradictory info if you look hard enough. Also, if you look hard enough you can figure out what is BS and what is fact.
Good luck
