New garage speaker placement?

If this a system to listen to while you work, maybe some powered monitors would be the best way to go. They can be placed on a shelf or mounted to a wall. No need to fool around with an external amp. You would just need a source with a volume control. (ipod, tablet, notebook, etc...)

Your best bet is to go to a music store, like Guitar Center. They have brands like KRK, JBL, Tannoy, Adam, Mackie, M Audio, and probably some others I'm forgetting. To be clear, I'm not saying these type of speakers will be as good, or better than traditional audiophile gear, but for a garage where you won't be doing any critical listening, they should work nicely. I have a pair of Tannoy 502's I use on a computer. I know they make a larger one with an 8" woofer. For your garage, those would probably be best.