Sounds to me like you are heading towards an ICV (individually constructed vehicle), which means fairly big $$ for engineering. If you want to go with a CA conversion You are probably going to want to throw away the front end and start from scratch. Some of the racers around may know better, but I seriously doubt if there is anything you can do for that transverse leaf setup for it to work ok if you are going to dump it and put on extra wide rims.

You are also limited to 25mm total track increase, so if you are planning 30mm extra width externally on each side you will also have to find 17.5 mm internally on each side. This probably will not apply if you go for ICV tho.

I'm sure it can all be don, i'ts just a matter of how much you want to spend!!