The cast lends itself really well to the genre, so power to you.
If you need some ideas for character-kits I'm certain that there are many here that can help with that.
I highly recommend calling it something other than a Touhou ARBA. This looks too much like a Touhou ABBA, which I don't even want to imagine.
What, can't you imagine Reimu performing "Money, Money, Money" in a flashy outfit?