TTB Swap to Solid Axle - Dana 60?

Ok guys. I know there is info all over the web on this but I keep finding scattered and conflicting info. Here's the deal: I have a 1997 F250 HD 4x4 7.3 powerstroke (older square body). Axle code on door sticker is 39 which = 3.55. I want to swap out the TTB with a solid axle, so I'm guessing Dana 60. Here's my dilemma and questions and I apologize for the ignorant questions up front. I've never done this.
1) I can't find a 3.55 front axle in Dana 60 anywhere. Does it have to match the rear 3.55?
2) What is the best year models to target to find one?
3) Anyone have a good source for one? Complete assembly ready to go.

I appreciate the help.