I have a few clients that would like to use afterpay or something like it. Afterpay is not compatible with Wix, do we have anything like that available now? Will we ever be able to add afterpay to our sites?
Ooh I love Afterpay! It’s currently a Feature Request, you can vote here to be notified when it’s released 
https://support.wix.com/en/article/request-using-afterpay-as-a-payment-provider