there are boards for every brand that use the variable rail design. it helps make edge transitions smoother and also helps protect the boards edges from dinging on sliders.
i have not rode many boards, but i can make a few suggestions based on knowing the features. the obrien decade and the new cwb faction have some very noticeable variable edges. the faction is quite smooth on the bottom but is continuous rocker whereas the ibex is 3 stage. the decade is 3 stage and quite simple on the bottom features apart from the delta base which is supposed to make the board ride faster only.
slingshot recoil might be something to try. it is 3 stage and is COMPLETELY simple on the bottom features. it will however have much more flex to it which i personally find great, but for you...? they don't have variable edges out of the box but the rails are shape-able with sandpaper. the flex of the board i feel adds to the forgiveness of the clean bottom.
this is by no means an exhaustive list. and of course it is all subjective in the end which can be frustrating, but very FUN... fun to experience new boards that is and find what you like by experience