eastbear copies have rails made for them, so straight fit if you buy the rails to suit. Bride rails arent much cheaper if at all.
i have a stock 33 seat at the shop, i'll try to have a look at it this week, see how hard it is to remove the rail from the seat on those.
if its not too bad, then fabing up an adapter to bolt the new seat to your stock rail shouldnt be hard - just cant sell off your old seat without teh rails on them