Ramstad is significantly left of Coleman, especially on social issues. For that matter, Collin Peterson is significantly right of Ramstad on social issues.
Someone who's piqued my interest as a candidate: Laura Brod, small business owner and state rep from New Prague.
Brod's votes in the last two sessions (links below) are pretty reliably conservative. 2008 votes
I’ll stick with Marty Seifert.