Some existing sites: Submit, vote on, and buy designs: http://garmz.com http://garmz.com - Closest to your idea. Promoting small designers: http://fabricly.co

Some existing sites: Submit, vote on, and buy designs: http://garmz.com http://garmz.com - Closest to your idea. Promoting small designers: http://fabricly.com http://fabricly.com Design fabric patterns: http://spoonflower.com http://spoonflower.com, http://fabricondemand.com http://fabricondemand.com Customize dress shirts: http://blanklabel.com http://blanklabel.com, http://propercloth.com http://propercloth.com, http://shirtsmyway.com http://shirtsmyway.com, http://worldofalfa.com http://worldofalfa.com