Count me in the "framerail" group. The whole purpose of the cooler lines and cooler is to cool the fluid. Running them between the engine block and headers seems counterproductive to me to say the least. I also don't like the rubber lines for obvious reasons, especially in the location you have them. I'd say along the block and hanging under the center link has to look worse than any "clutter" they could create at the frame rail (don't want to offend, but hanging under the center link really looks hack to me). I vote for hard line or braided line clamped to the frame rail.

Just my 2 cents......

Hope you get it running and have some fun with it soon.