As I understand it the problem with fuses is that they work loose and arc, causing heat and sometimes fire.

I think this is less likely with breakers.

Changing the whole panel is just like doing the two circuit panel but more wires. A little planning ahead will tell you if you have enough wire everywhere and so forth.

Or as an alternative you might be able to get an electrician to do it on his own time for $100.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.