I would say check out the designers at
http://xxxoutsourcing.com
Their designers are spot on and you get to work with them every step of the way which means you'll end up with a product in a style that would be suitable for your venture.
It's also well cost effective as you could have 1 of their designers working exclusively for you for a full month, all for the same price as it would normally cost you for 1 good piece through a design company.
