Plano is perfect and affordable. I can get one each of their 50 n 60-ish quart storage containers for $80 with$15.00 shipping from Cabela's.I don't know if you've got a princess auto where you are, but they have reasonably priced hard packs.
the first thing that popped into my head was 'potentiometer,' but I haven't a clue what kind of variable resistor I would need to look at for 120v 15A power.Ideally I think you should be looking at a proper Variac. I doubt a standard dimmer switch is designed for the kind of load an electric motor requires, but I could be wrong.