Ebay for Thule/Yakima stuff. http://www.orsracksdirect.com/ has decent prices. Either REI or Campor have some off brand bike holders that are identical to the Thule 591 for 20 or so cheaper.
My setup is:
Thule 369 Foot Pack
LB50 load bards
871 Fairing (helps keep the noise down a bit, esp with 3 surfboards on the car)
591 Long tray classic (for the bikes), qty 2
544 Hang Two Surf Carrier (for my surfboards)
I'm ordering an 830 stacker for my kayak as soon as the boat arrives.