I would think it would fit. OI believe our standard light has a 7" diameter. You may have to get a new set of headlight ears, but it should work. As far as losing/redoing some stuff...I think you should/need to keep it all. I'm currently rearranging my set up and wanted to do the same thing you want to. After some research I decided that I'm just going to change my tube-style fuses to blade fuses and relocate them. I'm also going to cut any excess wire to get rid of some of the spaghetti in the bucket.
Good luck and keep us updated.