I honestly think its a cool idea and I'm honestly debating on getting one. I still haven't found the right size PVC and I've probably spent more trying to find the right material. Id rather spend 15 bucks on something that will work all the time with the bonus of being able to change rather quickly and its not a permanent mod. I think is a good product that more people should be interested in. But hey, I'm just a dude who like to fling foam:)
I agree with Lunas, Plus the fact that you are putting quite a bit of time into it as well seeing that its 4-5 of them. Honestly, in order for me to be willing, I'd want to make at least a $200 profit on that. Its a lot to ask for but if you have the money, ill be glad to.
I think swirl would be cool. I have yet to try it but from the videos I've seen, its pretty good. I'd go for a blue, white, black. Like a galaxy kind of a thing. Idk thats just me:)