Thanks for your reply jggimi,
Interesting comment. Sounds pretty decent for a standalone solution. The more and more I read I am beginning to realize that sFTP is not going to be a practicle solution for my requirements however. (unless you can suggest otherwise? --which would be awesome!)
Right now as indicated above I have a setup that relies off of SQL to hold authentication information. According to the above SQL is not compatible with sFTP(OpenSSH). I imagine with some work it could be "made" to interact with the database through a custom script or something of that nature but that would probably take a lot of work.
I am curious about your comment "it supports any number of authentication methods including Radius servers" --there isnt a chance you would know of a solution for my SQL dilema would you?
Also one of the big questions I have that remains is with TLS. What sort of encryption does it use? Is said encryption "strong" enough like ipsec or ssh?
Anyway thank you again for your input.