If you want to spend less, and get more try the Samlex Power supply. SEC 1223 is the one you want. It is quite small, does 23amps continuously, and peaks out at 25 amps!!! It will handle three Mill, or equal chargers all day with no problems what so ever!! They run about 100 bucks @ www.hamradio.com
Check it out!!
Also Radio Shack's carries them on their web site, but not in their stores!!