I agree on your work - really nice stuff!
I just purchased an SQ-A; I'm eagerly awaiting delivery. It is coming with the basic prism. I know from past experience with a TLR that I'll want to pick up a waist level finder for it at some point, but the prices for them are just crazy right now. They seem to be going for as much as I paid for the the body, back, lens and prism!
Out of curiosity, did you end up using the prism or waist level more?