Before you spend a load of money like that you have to justify it. If the built in breakers cut out at odd times, are you talking about heavy load breakers, or what ones.
What would be the common elements in this setup that could cause breakers to trip? There are only a few, and you might have a loose connection in either the main positive feed to the unit, or the main negative feed out of the unit.
A loose connection acts just like a load and adds resistance to the circuit. That also adds heat to the wiring.
One easy check it to get one of those digital laser thermometers and point it around where wires make connections into terminal strips or onto batteries. Get lots of things going, the faulty breakers should be heavily loaded, and try to find a hot spot. You might just find the cause of your tripping.