Go to this site http://www.lurebuilding.nl/indexeng.html and go into the crank bait tab on the left. most of the templates are in metric but you can convert those and they give you the lip angles and weights required.
The farther away from the shaft that you can put the weight, the better, that's why I suggested something similar to a keel weight. Good luck with your design, it looks interesting.
The only issue I see with your design is that the weight of the lure is inline with the tie point. With the added weight of the upper spinner blades, I would think that the lure would roll to the side or even upside down. If you wanted to have the upper blades above the lure body (to prevent snagging) I would make the body profile more like a keel weight to counter balance the weight of the upper spinner blades.
I get mine from work. I use the coil out of a wire feed welder whip. we replace them every couple of weeks and they're 20 feet long. find a local welding shop and see if they'll save them for you when they replace their whips. I have about 40 feet of them sitting on my desk right now, and the price is right...FREE.
Try McMaster Carr. You can find them on the internet. here's a page from their catalog with neoprene tubing.
0328_001.pdf
0328_001.pdf
0328_001.pdf
0328_001.pdf
0328_001.pdf
0328_001.pdf
0328_001.pdf
0328_001.pdf
0328_001.pdf
you might want to try one of these www.detailmasteronline.com I use this to put in the feathers on duck decoys I carve. the pen will actually get so hot you can burst the wood into flames on contact. I believe they offer a pen tip shaped like a fish scale.
Bathroom exhaust fans are also brush-free and will work for exhausting a paint booth, they are also cheaper than kitchen hoods. I googled explosion proof fans and paint booth fans and got some good info that way.