Pretty much everything in Southfield that fits your price range will be busy during the weekday lunch rush. To minimize that, I recommend going earlier [[11:30 or so) or later [[1ish), if your employer will allow that.

As for dining options, here are a few options.

SOHO Detroit @ http://www.sohodetroit.com/

Central Park Deli @ http://www.cpdeli.com/ They'll allow you to place your order ahead of time on-line, which minimizes your wait time.

Bangkok Hung Cafe @ http://www.yelp.com/biz/bangkok-hung-cafe-southfield