I need to hook this unit up with relays, does anyone know if I can use 20amp relays for all loads that are rated to or below 20amps? I may want to add lights later on so instead of replacing relays I thought I'd buy them high enough before hand for future lighting additions. Also in the instructions it also says designed to activate relays with a coil rating no greater than 250ma., any ideas how to find this out before I buy the relays? Thanks in advance.