if you're looking for an ac regenerator, you might also consider the Exact Power unit.
the PS stuff regenerates all the power apparently at an efficiency of about 50% (or worse). this means it'll suck 2W to generate 1W of power.
the EP stuff only regenerates the "top" of the power. it apparently takes 90V of the wall power and then regenerates the top 30V to get you back to 120V. it's way more efficient. the units are much cheaper too and fit in standard racks. each can handle about 2000W.
i don't believe monster sells an ac regenerator.
doody.