Been surfing a 502 SP for the past couple months and loving it. It is the smallest board I've ever surfed but the short length and big volume makes the 1-3 gutless so much fun. Hooking little roundies and floaters on surf that most people don't bother to paddle out in is unreal. When it gets to 3ft the board allows crazy tail wafts and fins free maneuvers.
My recommendation would be to go as short as possible on the SP. Yeah it might not catch ankle slappers but the fun it gives you on the daily slop is worth it.