It's correct that the 97s are not officially compatible with 18 inch rims, reinforcement for the rear came in 98.
The rest is mostly bull****************, I suspect. At 81k miles, if the IMS bearing is still good, it's probably one of the OK ones. It'll be double-row - I reckon the later single-row bearings are dodgier.
My main objection to that car is that it's a Tip. Firstly, it's a sports car, so you want stick. Secondly, the 2.5 isn't exactly a rocket ship and the Tip saps power.
Here's my guards '97 2.5 on 17s to whet the appetite:
Good luck!