http://mysite.verizon.net/vze22yzp/id10.html
(links may not work properly now)
This is what I did, before I found that site. Have a 5 KVA and a 2 KVA that cost about $100 each, not including shipping. They're in a closet with a subpanel. They are fed 240V into the 480V taps. It's sometimes possible to feed them with 120V but, if they complain by getting hot and noisy, STOP that. For safety, I use hospital grade GFCI outlets. I even bought a regulated 1000W Sola MCR portable for $20 but those are noisy. For CDP's or other low power draws, a simple Hammond 500W is plenty, although not balanced. Balanced output derates the output current by half.
There is NEC provision for balanced power but not CSA. Grounding remains intact.
I've got 3 amps, crossovers, etc. and not a hint of noise or ground loop. Got a couple power cords from Ultimate Cables.
Some background with a wee bit of bias from Furman.
http://www.contractorsav.com/article/2006/11/07/ac-power