That means you can use either or not both.
You can choose which one you want to install but can not install both. You can try one out and switch sure. There are importers to import data between as these are different products.
I have Pro 7.01 working with
vb suite sure right here
A community photo gallery - ReefTalk Gallery
Payment is via credit card which if you have a bank account chances are you have a credit card as most banks you get a CHECK CARD which is a visa or mastercard it just pulls money out of your account
You can use paypal also and if you have no other means of payment you can mail via regular mail a check which would have to clear your bank before we would release the software.
The licensing is lifetime yes and licenses come with one year support and download access which means you can use the software forever on your site but you may need to purchase a members renewal say if 3 years from now you want to download say Photopost 10.
well you can install as a standalone although I think most users would need to reset passwords and some other things might need to be done since your user info comes from
vb. we only save basic user info in our users table when integrated with a forum.