PVC spacers mounted in between the side rails make for great chain tensors. We run them on the Kit Frame without problems.
Designing and building your own West Coast Drive or similar isn't that hard, provided you have basic milling machining available to you.
I want to see if my team can put this together before kick off:
http://www.chiefdelphi.com/media/photos/37147
Our breaking blocks are just a piece of 1/4 alum plate with 3 holes. One big one in the middle for a press fit bearing, and 2 on the side for 1/4-20s to mount them, not a lot of machining.