Right now they use frost bank, and upon reviewing they had like 4 million sitting in their checking account. At a bank with significant energy loan exposure. I want to ring their necks

I am looking for a total banking solution. They own a lot of oil and gas royalty interests and working interests (tons of small checks coming in) and outgoing checks for working interest JIB's. Mainly I would like a brokerage account to buy etfs and mutual funds to avoid going over FDIC limits.
I would be more comfortable going over these limits at a bank like Chase or BOA. But what I really don't know anything about is a business brokerage account and that is what I am looking for.
Basically what I use Chase checking and youinvest for on a personal level.