What spring sets to buy for B5M?

[MartC]

I've just recently got back into racing after an 18 year break, so still on a steep learning curve.

Associated spring sets aren't cheap, so can anyone recommend which sets are best to buy for a B5M running on a variety of surfaces? Mostly carpet and astro to begin with. I've started off buying the Medium sets.

I'll likely upgrade to the B6 sometime soon, which appears to run the same springs, so a worthwhile in investment