The SM-7 is a new discovery for me, love it so much that I now got a second one.
I got the best results with a UA 2108 preamp. Although I often use the Chandler TG-2 or UA 6176 for vocals with other mics, the 2108 is just amazing with the SM-7. Smooth but transparent, with a very low noise floor and GREAT low-end. I choose the compressor according to the voice and style, so I don't have a SM7-specific fave but a dbx 160VU works surprisingly well.
Andi
www.doorknocker.ch