I'm cheap so I went with a 7.99 soldering iron kit from Radio Shack rather than the clips. Came with the solder and a heat sink which helped keep me from melting all my flexwatt trying to get it soldered properly.

There's a definite learning curve if you haven't done much ( or any) cable soldering. I had to re-solder one piece a couple times because my original soldering attempts came loose, but I have the process down pretty well now.

For cheap cables I went to Dollar Tree, they have beautiful dark green Sunbeam brand extension cords for $1. For insulation and solder covering I used electrical tape.

I currently use the flexwatt 4" cut to basically UTH sized pieces and foil taped to the bottom of my tubs. So I ended up spending maybe $3.00 per "uth" rather than $22 at Petco or PetSmart or $12 plus shipping online.
I have a new AP rack coming in a couple weeks, I can't wait.