I am looking at getting pistons for my '98 GS-R. I have someone who has a set of standard ITR Pistons with rings for $200. Is it worth buying or should I go with oversized Type-R pistons. I am planning on getting a turbo soon. Or should I get different pistons than Type-R. Also they are Topline Type-R pistons, is this different than regular OEM Type-R pistons. Thanx for your help in advance.