Just looking to include something with a monthly dividend along with the qtrly.
Why? Are you in retirement and need the income monthly? That implies your cash buffer can only cover up to a month's worth of expenses, which seems like an unnecessarily risky way to live. Just keep an extra couple months of expenses in your savings account, and replenish it quarterly.
A quick glance at Vanguard's dividend-focused funds showed quarterly payouts (and generally at similar levels as VTSAX), but I won't rule out the possibility that there's one I don't know about.
If monthly income is your requirement, maybe you could look at Vanguard's Managed Payout Fund (VPGDX). Of course that fund doesn't have any dividend-specific focus, since Vanguard knows that a dividend-focus is a sub-optimal way to generate income.