Chris,
Thanks for your input and analysis. Something I did not make quite clear, and I apologize for this, it that although there are sales people, I am not trying to deal with the sales process itself, but the sales support function - Pre (presentation of product line to potential client, getting an appointment etc ...) and post sale, ie when the customer is a regular customer. ie documenting the sales relation, regular visits, quotes etc ... issues reported with the products and how the company handled it etc ...
So the problem at hand is at least an order of magnitude easier than what you imply in your example : (e.g. - what
does the system do if 2 salescritters, who are both offline, try to sell the same lots of product?)
In instances like that, my answer would be 'No can do, wait a few years until GSM 3G+ is available where your sales people travel or buy now a sat link'. but we are in a much simpler scenario which requires a small set of business rules which can be enforced.
I am already in the process of writing my own mix of front-end and Back-end systems that is aiming for "not too Complex and reliable" :) .