You can search on 4x114.3 mm or 4x4 1/2 bolt pattern rims. Most should fit but some may be tight around the hub center.
15's look pretty good on the P10's, 16's look even better but the tires cost a little more. The closest diameter to the OEM 195/65R14 are 205/55R15 (-.43%) and 205/50R16 (+.38%).
For replacing 195/60R14, use 205/50R15 or 205/45R16.
I will probably go with the 205/45R16 if/when for summer use and keep my 195/65R14 for winter. It's a shorter replacement but I want that 3% shorter "gearing" off the line, the slightly stiffer sidewall for less flex and slightly lighter weight to make up a little for the weight of the rim.
I took a close look at the rear tires and suspention on my stock setup. It looks like the bottom of the spring is just 1/4 inch above the top inside of the tire, with size 195/60/14. Has anyone put larger (diameter) tires on? Especially with older P10s. Was there a change in suspention setup in 93, I know the 93.5 had larger tires.