Depends on the king of game you intend to play.
Basic skirmishes don't require a radio. Larger scenario-based games with squads organisation usually require (or very, very highly recommend) having one, and it's pretty much mandatory for milsims.
As far as waterproof boots, it also depends on your kind of play. I know some guys don't care about going into swamp areas, and that always fill their boots with water... in that case, it's better to not have waterproof boots: they will get filled anyways, and if they're waterproof, they will stay wet.