the cheaper specialized mtb shoes squeak. just saying. its worth the extra scootch to get the better grade ones.
also, cycle shoes should fit glove tight. shoe fit is a very individual thing, so you're best off to try assorted brands to see what fits.
me? I wear new balance 'mw956' walking shoes, which are what I typically wear when I go out for anything other than dress, and I use bmx style 'pin pedals' on my hybrid. I used SPD on my last full mountain bike, and while I got competent enough at getting in and out of htem, I was never 100% comfortable. I *used* to use toe clips with Detto Pietto racing shoes on my old road bike, and the metal cleats you had the cobbler nail to the shoe soles (one chance to get it right!).