I have one of these and if it is really room you thirst for you can buy this and hook it to you belt. No charge up wait, no plug, and it will drive a LOT of nails before you need a new cartridge. I would recommend at least considering this even if you get an air compressor. You can click on the demo for more. Try and get the kit that comes with a cartridge and use a Lowes discount if you can find one.
http://www.lowes.com/lowes/lkn?actio...735-J-6901-100
Dewey