While we don't offer panel layout yelp per se, we're always happy to talk to you about general panel configuration. There are a a few panel planner websites/programs out there, but we're not familiar enough with each of them to offer recommendations.
The Vans Air Force forums are always a good source of information.
Finally you've also got panel builders like Aerotronics, Stein Air and Stein Air that would really prefer to sell you a full panel, but may also be able to offer some advice if you buy through them. The and a few other of our dealers are listed at: http://www.dynonavionics.com/docs/Dealers.html