Recommend Resource For WP Developers

Hi –

I am looking for a reliable web development company that specialise in WP and its plugins.

Question: Can you recommend a website which has a good listing of developers from which to choose?

Its for a knowledge hub which supports social networking between Experts (members) and members set-up project listings to buy / sell solutions. Members & Visitors san search for Experts and search for Listings in categories and using key words.

Possible plug-ins or similar
BuddyPress
BePro Listings with expiration of listing
e-commerce