I just installed the Bussmann Accessory Replay Panel I got from Amazon. This is a kit includes a Bussmann relay and fuse panel in a weather-tight gasketed enclosure, some barrel crimps, heat shrink tubing, and some cable ties. The unit has 5 individually controlled relays, each circuit has a fuse for the load, a fuse for the control circuit and a fuse on a "constant hot" supply circuit. You can read about the installation here.

bussmann relay