Apple tv/ Airport express/ airpaly question

I was just wondering if i can use an apple tv without a monitor. I want to use it like an Airport express would be used to stream music from my PC to an audio system I have setup outside(receiver inside at backdoor wire run outside to all weather speakers) or will I need to have a display hooked up for it to work? The reason I would want the ATV over the Airport would be nice to have the option of video in the future, not to mention I see used 2nd gen ATV on ebay for $75.