Transmission Changes

[utilitarian]

My '96 F250 HD Supercab is running a mostly stock 7.3 DI Turbo with automatic (A4OD I believe ). As I understand this transmission is commonly the weak link in an otherwise awesome drivetrain, I am considering the change to a manual transmission of some sort. I have always preferred to do my own shifting, especially where diesels are concerned.
My concerns are:
1. What would be required to make the various electronics (computer, speedo, etc.) accept this change?
2. With weight and my current 3.55 rear axle as considerations, and the desire for improved MPG through proper gear selection, what transmissions are good candidates for installation?
3. And finally, any reccomended souces for parts and/ or information, would be much appreciated. Thank You for any and all input.

[Raul@Stealth Automotive]

not sure on any of your questions but here is a Bump for ya

[utilitarian]

I appreciate the information, I will check out the sites you've linked to me. I'm sure I'm not the first to want to make this kind of change on a Ford. I've seen some interesting drivetrain changes on Cummins Dodges. The one thing I have seen though, is that some of the transmission choices are inappropriately heavy for a pickup truck. Thank You again, Rob