Hello to all!

I'm preparing to build an Avenger (or similar), the first one in my country.
I'm making drawings and start with molds as soon as I've prepared the donor car, 3 door Ford Sierra XR4 with 2,9i engine.
Due to this, I have some questions.

How should I come up to gearbox? The standard Ford 5g is ment for front engined cars. Should I modify this box or maybe install some other from mid-engined car?

Also I'm planning to build the body from scratch, as I found out that ordering it from USA is too expensive. I could save this money for engine performance. I've done pretty big body parts from scratch before, so I guess I can handle it. Why I want to do it myself, is that I want to use Sierra's glass, that's cheap and easy to get in Estonia. Also I've drawn some custom mods for the car. I guess it's easier and much cheaper to start on white sheet, than completely redo stock Avenger.

Also a question, that I've never experienced a kit car so deeply, I've been helping to build one in Sweden, but I have forgot the solutions for mounting. Maybe someone can send me photos or something about the mounting points etc? I would be thankful.

The reason I want to use Xr4 engine, is that I can do all performance mods myself. I really can't see a point of taking a hobby-car to the service. I better do myself and "eat that soup" later - I know what I have done. I have modified many Ford engines before, and as I'm a fan of this mark I planned to use the tech parts.

I think that gearbox is my main problem at the moment, and also the mounting points stuff, if someone is willing to help I'm very thankful!
Maybe someone also knows something like build diaries in the web also, I'm interested in links.

All have nice day and safe & fun driving !