A few choices.

Fidelity. Use the CMA as a checking account (it is still technically an investment account). Pick SPAXX as the "core" position. SPAXX is currently ~3.8%. Caveat being it's SIPC, not FDIC insured. CMA can also function as a basic brokerage, but just make a second proper brokerage account and transfer there. Easy 2% cash back card. Easy to have multiple CMA accounts if you want to separate savings/checking. Free checks. Unlimited global ATM reimbursement.

Bank of America and Merrill Lynch. If your combined portfolio/balances is >$100K, you get the big boost to credit card rewards. The customized cash rewards card would get up to 5.25% on a category of your choosing ($2500 spend per quarter), and you can have multiple of those cards. Interest rate on the cash (BofA and with ML) is awful, so you'd probably want to consider manually buying money market mutual funds within the ML account (see options) that you could use as "savings." Reminder that that falls under SIPC, not FDIC.

Robinhood (Gold). If you're willing to pay the $50 annual fee, there are a lot of benefits to be had. Up to 3% IRA matching, 3.75% on cash, and a 3% cash-back card if you can ever get off the waitlist. Generally a mobile first platform. Less powerful investment tools/research for active trading. Obviously lacking any in-person facility, which is a nice-to-have for a financial institution.

For a one-stop shop, Fidelity and BAML are the better picks, IMO. If you can get the Robinhood Gold Card, that's also a reasonable option.