gonna have to agree with this. I just finished up my interviews for quant and the faculty members are all very aware of the fact that most undergraduate students don't have access to pure quant professors, so I imagine many people would be more than happy to help!
also, regarding your primary question, from what I understand, while quant PhDs are in high demand, even just minoring in quant is a great way to get a competitive edge if the area you are maybe more passionate towards is a little more competitive.
good luck with it all! PM me if you think an anonymous dope who just went through the quant application process can be of any more assistance.
~L'HP