Clueless

Alright readers, I've got a serious question. As you all know I have been frantically searching fora job here in Starkville. Well I made it past the first round of interviews for a job (it was a phone interview), and now I've got second rounds coming up. This will be a face to face interview with the manager of the company. We are meeting at Starkville Cafe (a little down home cooking sort of joint) at 9:15 in the morning. My question is WHAT DO I WEAR?? I mean, I haven't been on an interview in like 5 years... and the fact that this seems somewhat more casual (I mean we are meeting at a southern cooking restaurant in the morning) I am at a loss. I mean I don't want go the business suit route because number one it is freaking hotter than face of the sun outside and number two, as I mentioned, this seems a little more laid back. Let me give you some background. The position is for a customer service representative for a medical equipment provider (ie - they sell medical equipment such as breathing machines, mobility machines, etc.) The first interview was over the phone since the majority of the job would entail talking to people over the phone. Now, its face to face time. HELP!!! I am totally lost as far as proper summer interview attire!!!!