Being "limited" to smaller speakers is not an issue for me as desk space is a major consideration. Having said that though, I'd be looking for some level of quality from this sort of setup. The Audioengine A5 is well reviewed as a set of active speakers (I've not heard it). Hopefully the A1 can at least match it, when fed with a good source and paired with good speakers.
Any suggestions on where to start looking for small but great sounding passive speakers, that would be adequately driven by the A1?