CM303

I'm developing a set of services that I would like to package for people to be able to buy easily through the site rather than using a scheduling app to set up a discovery call, then setting up an invoice to be paid through a different service, then sending out a manual contract in a different service. Does anyone have experience doing this as a digital product, or is that fitting a square (space) peg in a round hole? If so, any all-in-ones you like out there? (not a fan of honeybook).