Looking for new Mini

I see RCM's chassis is also wider. How much wider is it compared to the stock one or compared to the Ofna extended one?

IF going for Mike's chassis (which I like alot) will the stock body fit ?

There are blue springs and white springs as options. Where do the standard springs (grey) fit. Is this hard/medium ?

I also have some Losi springs, which seem to fit. Anyone uses those ?