Voltage and amperes standard input requirements?

[Rkiser]

Im trying to set up an outdoor sound system at my home. From what I've found I have a lot more options in terms of space and control requirement if I'm using a car audio head unit to control my system outdoors. I've priced and configured everything except for the power supply. I've seen tons of choices in ac to dc inverters/bench top power supply with 12v supply and amp ratings of 10 to 200. My question is: is what is the minimum amperes from a power supply that I can use to power a basic head unit at my home? Thanks in advance.
Rob

[BrownVanMan]

If your powering nothing more than a regular hu (non touch screen) a 10 amp should be fine.