i can second the odyssey brand-if you get a used one find the id numbers first and call klaus to make sure its a real one, a expartner of his sold amps with odyssey name and they arent built right, klaus wont work on them either.
theres a fake at audiogon right now for 725$(the ripoff jerk sold these for about 500$)
i love my odyssey mono blocks with extreme upgrade, i have 4ohm 89db speakers and they never break a sweat, oh man they sound good.