just bought leupold w/40mm,obj,30mm tube for my ar15 flat top w/rifle length quard rail. what height rings should i buy? and what kind? i don't want to wait until the scope gets here to order.
If you want one that quick releases (and returns to zero when reattached), consider the LaRue LT-104. Mine is awesome, whether it's worth 3x the price of the Chinese made P.E.P.R. is up to you. Also consider the Bobro mount; I've heard good things about it, and its advantage over the LaRue is that the quick release cams do not mar your upper because they act against a clamping plate, and not directly against the upper.
Also, SWFA sells a variant of the P.E.P.R. without the rails on top of the rings if you don't like them.