patshep

i have to say an sm7 alone is not the main vocal or acoustic guitar mic i would want..it works well on some kinds of vocals, but a large diaphragm condenser will probably be more of what you need

the akg414 is probably a good choice, not flattering, but honest on vocals and good on acoustic, you can find them fairly cheap on the used market also, around $550-600, take the extra cash and get an sm7... i'm about $100 over budget, but it's worth it

i've never had problems with motu's customer service, they have been good for me... a little wait, but not bad, i've rarely had to call them, everything is pretty stable and well explained in the manual