Well, I have good news, and bad news.
I designed a somewhat simple motor mount on some free CAD software (eMachineShop), and I got some quotes. Lowest I can seem to get is around $150-$200 US for a single production. So, it seems that getting it milled is pretty much out of the equation. I think I will just have to try and fabricate it myself (grrr), unless somebody knows somebody/someplace that could do it for cheap. It's not too complex of a piece, 1cm thick, milled out to 5mm around the motor, with 9 motor holes. I'll post some pictures of it when I get home.