Thoughts and Ideas on Battery Powered Amplifiers?

I am looking for a high-quality battery powered amplifier. I have seen a few listed on eBay and one from DIY Kits but I figured I would ask the crew here to see if such a beast exists. The power to my condo is noisy and fluctuates between 100 volts to 122 volts. The frequency is solid, relative to the voltage.

I would rather invest in a battery system than big $$ on line cleaners and isolation. I have a medical grade trip-lite line isolation box and step-up/step down transformer that was used for NMR machines at the U of I lab. It does OK, but I think DC to DC is the way to go for purity of sound without huge $$ on electronics.

Any thoughts? Under $1k for vocals, singer/songwriters, blues and loads of jazz. This will be used with Totam Hawk speakers, McCormack Line Drive passive preamp, Linn Sondek LP12 and Ray Samuels Nighthawk battery phono preamp I am about to order.

Thank you in advance – D
Analog_source, problem with most of amplifiers is that its linear power supply is unregulated and it is AC only. Switching power supplies on the other hand are load and line regulated and often work on DC voltage. Some are better some are worse. Computer switchers are horrible but Icepower built in are very decent. Rowland uses new 1MHz switcher in Model 625 (class AB) amplifier. This power supply is extremely quiet with zero current, zero voltage switching. Many people believe that power supply has to have huge transformer and a lot of electrolytic caps while transformer of the same power at 100kHz is 10x smaller. Also electrolytic caps are smaller because frequency is much higher (filtration). Finding amp with regulated power supply would perhaps be the better solution than using external regulators or batteries and inverters. Switching power supply, like one in my Rowland 102 (Icepower) works also on DC making it immune to presence of DC on AC line (subject of headache for many).
I have a battery powered Tripath Class D amp that sounds as good as any amp I've ever heard.
Custom made with all top quality caps, WBT inputs, and Cardas speaker outputs. 45 wpc at 8ohms and 90 wpc at 4ohms.
I am very happy with it.
Red Wine Audio has some