I'm a little late to this party, but I recently made the jump from a bulky, full wallet to a minimalist wallet. I went with one from MSTRMND Collective (http://mstrmndcollective.com/) because I found their project on Kickstarter a few months back. I was able to get http://mstrmndcollective.com/products/apex-wallet-black-horizontal for $22 shipped, which was a great deal in my opinion.
I expected to face at least some discomfort since I wasn't used to a hard, metal wallet, but I've had no issues with the transition so far. Honestly there have been plenty of times where I thought I may have lost my wallet because I couldn't feel anything in my pocket. I currently have 5 cards in there, and while you could definitely fit more this feels like a nice size. If I ever need cash, I fold it in quarters and stick it between the back card and the elastic.