i have a s-rail its so fun any time go out and have your own session but i would do a up to flat to down but make the parts removable so you can have like all these different rails
up rail
flat rail
down rail
up down
up flat
flat down
up to flat gap
up to down gap
up gap flat gap down gap
flat down gap
that is all taht i can think of now but ya that is the best im building one now