That Boss is going to run hot enough to scramble eggs at 1 ohm, just saying. That's what I meant by seeing if it was capable of operating there for extended periods. I'm sure it'll work, but for how long without overheating is the question. If you really want to use that junk I'd at least plan on some auxiliary cooling fans.
Also don't use a capacitor. That's what the new alt and battery are for. I've seen capacitors cause more problems than they solve in almost every instance, they're a terrible band-aid.
EDIT - Also just putting this out there, but I don't trust that RMS rating on the amp at all. I'd be curious to see what it actually puts out, but I'd bet $100 you'll never see 2K watts at 1 ohm. Boss, Audiobahn, Planet Audio etc are all terrible about over rating their stuff.