Well in order of goodness I think it has to SMS200 then Aries Mini. 2nd hand they are hovering around the same price I think.
If you are not able to use the USB output on the SMS200 then that means you have to go for a converter. I have used both the XMOS based units and of course the PUC2 Lite as you mention. I have not used the top-of-the-heap XMOS Singxer U-12 though so you'll have to read my comments in light of that.
XMOS (in general) - subjectively has what I would call a slight "V" - heaps of bass and a slight treble forwardness - not bad by any means and perhaps good in the right system but not good with a Devialet that already leans that way. Very clean and clear and quite "juiced up".
The PUC2 Lite (shameless plug - I have mine for sale) is a very different sounding beast. Much smoother, bass and treble not exaggerated in any way - very much more oriented towards digital haters / vinyl lovers who might be put off by brightness or general in-your-faceness of digital (or at least the perception of what digital sounds like). I found the PUC2 went well with my system over the time I've had it. I found it quite relaxing to listen to. In the end, the best combination was SMS200 - PUC2 Lite - Devialet. Now that I've wondered into Class-A Pass Labs and the DSJ I find the PUC2 unnecessary.
The SMS200's do pop up 2nd hand on here so perhaps you can get one at a good price. And as I've said before, if it doesn't already come with one, get an aftermarket power supply - an IFI Ipower can be had at sensible prices. So in terms of outlay, if you went 2nd hand you might get the 3 for perhaps $900. I don't think you're going to see Aries for that price 2nd hand so you'll still be spending less. You might be able to grab an AIRES LE at that price but then, bugger, you've got to get a power supply to extract the best out of it!
Hope that doesn't leave you more confused that before
I can give you the loan of the PUC2 Lite if you are at all interested. At least I can find out if other people hear it the way it do!