Apart for a DC disconnect for solar panels, I sugest you use quality fuses for over current protection in your DC system.
Buss bars incorporating fuses are available,
High current copper bus bar for 5 circuits in parallel with modular mega fuse holder. Battery protection. Made by Victron this bus bar is rated at 1500A and connected up to 5 circuits in parallel with mega-fuse modular blocks. DOVETAIL FEATURE The dovetail feature allows interlocking multiple...
voltaconsolar.com
The Lynx Power In is a modular DC busbar used to connect batteries to the Victron Energy Lynx DC distribution system. Rated 1000A at 12, 24 or 48V DC.
www.12voltplanet.co.uk
For small systems,
Compact power distribution & fuse box that distributes power theough a single mega link fuse into 4 midi or strip link fuses.
www.12voltplanet.co.uk
For isolation , use switches,
m-Series 6006 Mini On-Off battery switch from Blue Sea Systems rated 48V max. & 300A. Suitable for harsh marine environments.
www.12voltplanet.co.uk
Almost all the DC breakers on ebay and Amazon are unreliable, overheat and have excessive volt drops. You can get Bluesea, Bussmann, breakers but are expensive,
285-Series panel-mount ignition protected IP67 manual trip & reset circuit breaker for safe use in marine environments around fuels. 25-150A ratings available.
www.12voltplanet.co.uk
Even with quality breakers there will be a greater volt drop compared with fuses, once you are over 150 amps this may be an issue.
For lithium battery main fuse, at 12v a MRBF in blue sea holder is acceptable, idealy and at 24 ot 48 volts, class T or HRC fused are needed,
Fast blow Class-T fuses in 225-600A ratings for protecting cable in high power applications. e.g. where power inverters & lithium batteries are used.
www.12voltplanet.co.uk
As a newcomer to DC systems , breakers seem attractive, can be reset, however in practice the overcurrent protection will rarely operate.
DC breakers seem more common is US derived DC systems , unlike Europe where fuses are more common.
If you post some idea of your proposed system more specific suggestions can be given.
Mike