I did tons of research on amps to pair with these speakers. This will be long and detailed, so if you're not worried about finding an amp (or a subwoofer), don't bother reading :).
There's ton's of small power amps out there. Keep in mind that these are only 4 ohms, and most amps give their WPC rating for 8 ohms (usually the 4 ohm rating will be around 50% - 100% higher, though often if someone says an amp puts out double the power at 4 ohms compared to 8, they were usually too lazy to test this, because rarely (if ever) is an amp ideal enough to stay equally efficient with lesser impedance loads). I actually talked to Michael Goodman (director of CEntrance) at T.H.E. Show this year, and asked about the speakers, and he said 40 watts is usually enough to blow them. That said, keep in mind you can never have too powerful of an amp as long as you don't mind being careful with the volume control, but you should be aware of your speakers limitations.
Some of the amps I looked at in addition to the CEntrance Dacmini PX are the NAD D 3020, Rega Brio-R, Music Hall A15.3, Cambridge Audio Topaz AM10 and Azur 351A. I think there were others too, but you get the idea. I'm probably going to get a NAD D 3020. The reasons being, I want an amp with a relatively small foot print that puts out around the ideal amount of power (it's rated at 30 WPC @ 4 ohms). It's also been extremely well reviewed, including from Stereophile. Most of the other amps I looked at were considerably more powerful at 4 ohms, which I don't need. I also wanted a subwoofer output, because these speakers are going to become my primary setup on my PC. While they put out enough bass for music, my computer is also used for movies and gaming, where it is nice to be able to get the effect of a subwoofer. The NAD D 3020 has a subwoofer output (any volume controlled line-out that shuts off when the speakers shut off for headphones will work). I'll get to my subwoofer recommendations soon.
The DACMini PX -> MC 2504 setup sounds great. I've heard it myself. Don't let my own choice for an amp make you think otherwise. The main reasons that I want to go for a NAD D 3020 myself (anyone want to get a drop going? I've tried) are the subwoofer output that I mentioned, and the fact that while I haven't tried them side by side, I'm sure the power amp section will be better (and was doing research on power amps, not DACs, as that's something I'll probably upgrade in the future anyways). The reason I say this is that DACMini PX is designed as a DAC with a built-in power amp, while the NAD is designed as a power amp with a built-in DAC. That said, I'm sure the DAC section of the CEntrance unit will destroy that of the NAD, but again, that wasn't my primary concern.
Lastly, for subwoofers (I've tried to get a drop on small subs going in the past too, but without luck), I'm thinking of getting a NHT Super 8. It's very affordable ($350), and along with its matching SuperZero satellite speakers, has been very well reviewed (again, including from Stereophile). It's rated for 110 watts, which pairs pretty well. I was originally looking at a Velodyne MiniVee, but it's a lot more expensive, and 1000 watts, so I probably would've needed to keep its level very low to pair well with the speakers, which would be a bit silly. Above all, I wanted a subwoofer that was designed for music, as most of them out there, especially cheap ones/small ones are built purely for home theater use and do not handle music well at all (they don't control their bass well, or don't have "tight" bass as is often said). The NHT subwoofer actually has a switch on the back to change the EQ between music and movie modes, so music was clearly thought of. I'd love to find a preamp or integrated amp that fits my requirements that also allows me to quickly switch off the subwoofer output in case I find it over-bearing for music, but oh well, I guess I can't have everything lol.