If you want good seal then spring for the Total Seal rings. I use those on engines I really care about and while the cost seems like a bit much compared to a cheap moly set they really do have zero leak down. Pro's say they're only worth 5-10hp which isn't much- but they also give you cleaner oil and improved vacuum which helps on the street.
Last time I bought a set I think it was about $150- and you can get a set of cheap moly rings for like $40 so again to you the sticker shock may not be worth it. I've used both and for some applications a std moly set is really just fine and sometimes I want something a little better.