Thats a good one. I have used my stock 195-60 14s and my
215-40 16s. With the 16s it was a little more of a ruff ride during hard cornering and i noticed that the 14s gave me more under steer, but it might have been because i had the tire pressures set for the track (on the 14s).
As for damaging your rim, can't see that happening. I have been in cars with 18s using 35 profile tires and really stiff suspenion and there was no problems.