Like I said, I haven't heard the ART, but I do know that I can get good results from an SM57 that are better in mixes than the C1 (not saying one is better than the other but in certain mixes an SM57 works better).
As far as preamps go, I used to track everything with a Spirit by Soundcraft mixer. After getting an MP20, I have been able to track vocals with everything from a C1, SM57, and even the infamous Radio Shack tom mic (just yesterday... still mixing).
So, in other words, too many factors to consider. If you don't got the money, do the best with what you have. Playing with the position of the mics may help you more than buying new gear.