I imagine no one's really going to give you anything negative about any of the houses at Mizzou, especially on GreekChat. There are several Mizzou alums, advisors, and other members familiar with Greek Life there, so hopefully they'll chime in and let you know how it's like.
If you haven't done so already, a search on Mizzou might bring up rush threads from past rushes. A quick Google brought up this:
http://www.greekchat.com/gcforums/sh...ad.php?t=95478 -- she's a transfer and incoming sophomore, but the advice given there might be useful.
The General Advice thread stickied at the top of the Sorority Recruitment forum is a valuable resource as well. Pay close attention to the part about Recommendations. Recs are important things to have, and even though some PNMs might have received bids without them, that's not always the case.
Best of luck to you!