Planning? Hmm, it was originally going to be an all steel welded rack, but seeing that I did not have a welder or find someone to do the project withing 2 weeks, I decided to line the top of the rack w/ wood. The east part was getting the mounting hardware to anchor to the roof. I had to purchase two sets, as one set only contained two pairs of supports. I still have a pair of supports if you are interested in them. Brand new. They're $42-50 online, link:
http://www.everythingsuv.com/surco_safari_roof_racks-esuv.asp, Surco TR-100.
These supports fastens to the factory mounting holes, you have 3 on each side. As for space, wow, you got plenty of space for a kayak and a bike. The steel tubing measures 54" long, and those spruce timber where originally 8' long, I had to cut it down by 7", so it wouldn't look so funny (well funny to me). I didn't want the wood to be vibrating at freeway speeds so, they went and saw Mr. MiterSaw. If you are creative enough, you could easily cut and build a kayak mounting system on one side, and bolt a piece of wood across the top section and mount a bike quick release to it for your bike, then just strap the rear wheel to one of the wood supports.
There's plenty of room up for both!
Faring is made of lexan, pricey but worth it. They typically last longer than plexiglass and does not crack as easily. It measures 48"x12".093".