Yes I know they have been hashed around a bit. I was just hoping that at some point in all that hashing someone may have whipped up or found a compilation of how to work with El tape. I am not exactly mechanically inclined(yay for a paleontology degree) so I am a wee bit inept in this sort of thing.
Your still going to need a power supply (batteries), assuming you want to move around. As you will note from the kit picture you posted, they show a wall socket "power adapter." A few smaller inverters come with a spot to put a battery in, but probably the majority contemplate an outside power source. The whole how long your battery lasts and getting the correct voltage gets a little tricky, but nothing someone can't learn with some diligent reading.
There are battery packs/holders which can get to your desired voltage using commonly found batteries. Plus, you can get some nice run times out of these. Cutting, soldering, and the wiring requires some planning. Before you cut anything, I recommend making templates with paper or whatever so you can see how it sits on the fabric. Also plan and diagram out your wiring.
Honestly, after you figure it all out, the costume design and integration of the two seems more challenging.