Need suggestions for a TURNTABLE MAT...

change your glass platter for the acrylic platter and use no mat.

I used to have a Rega 25 with rb600. The ringmat was a big improvement. Ditto for the heavywight. Everyone once in a while you'll see them used here for about $50 bucks each. Well worth it for that kind of money.

Agree 100% with Jfrech on both the Ringmat and drop counterweight (Heavyweight).

If you want to experiment cheaply, you might try the cork turntable mat that sells for around $10 (I think Audio Advisor sells it). Depending on what kind of sound you want (somewhat lively rather than heavily damped), this mat is surprisingly good.

Oracle was very proud of their mat for the Premier Mark IV, which I have. But a Ringmat made a major improvement. With a Rega, you should get the thinnest Ringmat, unless you add a VTA adjuster. At least with some cartridges, the thicker Ringmat(s) would throw the VTA off and hurt the sound. I have a Rega 25 too, and use a Ringmat on it with excellent results. Rega and Ringmat are a famous combo, I think.