An electrical sub-forum is a *GREAT* idea! (Says Kal as I sit here writing up how my control panel was built for my new www.TheElectricBrewery.com
Back on topic:
I feed 10/3 (30A/240V) into my control panel. A 30A breaker sits in the house breaker panel to protect the wiring in the house that goes to the control panel. A GFCI sits in the cord that plugs into wall socket into the which the control panel plugs. This protects the brewer.
I don't feel that additional breakers are neeed in the control panel, but I do use a single 7A fuse in a holder ($2 total) inside the control panel. It's placed between one of the HOT (30A/120V) inputs to the box and the 15A/120V hot bus used to power my PIDs, lights, pumps, etc. Normally no more than 3-4A should be flowing into this bus.
I don't understand why you'd use a more expensive resettable breaker for this as it should only trip if ever there's a catastrophic failure of some sort. If my 7A fuse blows (worth 10 cents) it's because something failed completely and needs to be repaired. You don't just reset the breaker and replace the fuse.
This is different than a house breaker panel. Resettable breakers make sense in that sort of setup since you never know how many things may be plugged into a circuit so the chance of tripping a circuit breaker are much greater. With our control panels that is not true since they're closed systems.