Hello, I have spent many years playing, creating and hosting open sim as well in Second Life, so I'm quite familiar with the infrastructure and their scripting language.
I also have experience working with Paypal Rest api. Stripe is something I would leave for the end since I have no experience, but should be no problem to get into.
We would need hosted sim in each opensim world, with scripted object, that will give players balance once the payment is confirmed.
"tranquility dollars"