Hi
I cant wait to read about what your going to do.
I agree the 1303 dash is a pain. I've made mine a little easier to deal with, I moved the fuse box into the trunk and made all the panels across panels across dash easily removable. I fitted M5 nutserts to the dash and held the panels in with M5 screws.
Cooling with any water cooled motor can be taken care of by fitting the radiator in the front and using an air con front apron.
Steve
My fuse box