fuses are more finely adjustable, in that you can get more minutely stepped variances in ratings, and fast reacting or slow blow, etc.. a ckt breaker doesn't require anything to be replaced if it's tripped, and can be had in an auto-reset moel. you generally use a breaker for high current lines like by the battery, and fuses for each amp to protect the electronics.
Oh ok^^,IMO circuit breakers could save you some money in the long run but if you change setups your circuit breaker might not match up with the amps of your new setup so you will have to buy another one,where fuses you can put any size fuse to match up with your setup.So ill prolly be going with fuses.
any car audio store.. lol / I payed 5 bucks for a 200a fuses, all day... U can also check a boat store, they carry alot of ANL fuses, all types! ranging up to 500a!!!!!