hatchling rack

I'm currently working on a new hatchling rack and i'm trying to figure out the best way to heat it. I wanted to use the 11 inch flex watt and do back heat but since i'm using left over melamine I can only fit 3 tubs which end up being wider than the heat tape and not worth getting another piece of 11inch. I could get another piece of 3in.

If I was the use the 11 inch and 3 inch... Do I attach it to a piece of peg board?

Or...

I've seen some people say they use heat rope.. Is this better? And how would I lay it out? Pictures would be helpful if anyone uses the heat rope.