If you, Ronald A. Richardson
is still thinking/searching for a developers i would suggest following.

1st. with all respect to the PHP developers and the platform itself, i would suggest not to use PHP+MySQL for big projects, you may get surprised on its stability. once we spent 2 month making the gaming portal handle huge traffic. (but anyway you may ignore it.

2nd. you really should make few projects out of this one. and do it step by step. if the developers, that were doing first project did good, you continue using their services. once project (part of the big one as a separate site) is done, you can spend some money on its promotion.

so when you do second project, by its end you will already have working project (the first one) which can be used for the site's promotion.

our team has experience with both big projects and smaller one (design+development and its promotion)
you may want to contact me and i give you consultation FOR FREE, just to share experience.

i will say much more arguments which i can't do on public - and it may help you to do business.

good luck anyway.