Re: Does anyone know of any legit instant payment services okay with porn
Well, DLSite is its own store where they allow you to buy points which you can then use on their products (at a discount even if you buy larger numbers of points). You need a credit card for them though and that doesn't apply to products outside of DLSite.
The other alternative is pre-paid credit cards, but the short answer to your question is no, as far as I am aware of.