Ok, I have single payments working using their Elements API with simple Charges API (no customer objects). The credit card form blends directly into CBSubs so users have no clue it's even Stripe. I'll be reviewing supporting their Checkouts API (popup) as well. Still have IPN and Refund handling to implement, but all in all pretty simple to get single payments working. I'm guessing it'll all be done late next week (I don't work weekends and I'm done for today, sorry!). Below is a screenshot of stripe payment successfully working.
Some metadata is sent. The invoice is the invoice number as seen in CBSubs. The order id is the basket id in CBSubs. I'll be adding user id to it as well.