Have looked at FoxInCloud but it won't do what we want it to do without a great amount of rewriting and restructuring unfortunately.
No matter what you choose, this is the world of web applications and will require a huge amount of restructuring and a huge amount of scaffolding to even deal with security properly, even before you get to actual business problems.
FoxInCloud has the advantage of providing a framework for getting you some of the way there from an existing VFP solution.
You might find that putting the existing solution on a Windows server in the cloud and allowing the users RDP access is a path of less resistance - in that scenario all the DBF access is happening locally on the server.