The powergate thing is an automatic switch, a good idea for unattended setups like repeaters, and for continuous operations that are hosed by even very short downtime. I think for base station use, the automatic switch isn't really needed. If the AC power goes out, you're off the air until you unplug your rig's AC power supply and connect up the battery supply, probably not a big deal even if takes a couple minutes. Anyway, yeah, deep discharge marine battery of gel cell with a trickle charger is the usual ticket. A fancy charge controller is overkill for this application. A battery friendly radio like most typical moviles seems like a good idea though.