There are many questions you should and have asked.

1. Skill set of your shop?
2. How application will be used and by whom?
3. Security - what type and degree of security is required?

One approach I would suggest is to take a look at Visual MaxFrame Professional. This like any framework, requires a learning curve as does learning a development language. If you require security to the component level it is very easy to include with this product. Trying to develop your own framework will take a gread deal of effort and if the hours are not billable not worth the effort. Let someone else develop the framework and your shop develop the applications.

Tom