If I install a meter load center (meter can and breaker combo) can I use a lug panel for the main service panel?

The meter combo IS the main service panel.
The panel on the inside will be a 'sub' panel; assuming it is fed from a breaker in the outside panel.
And don't forget to pull a ground too.

I'd still use another main panel inside though.

I doubt that I'd install a main in the sub panel since it is within the same building. Still, those panel packages that come with a main PLUS a selection of breakers are sometimes less expensive than buying a MLO panel and the same breakers that come with the package. Kind of hard to argue at that point.

A 100 amp MB panel with five SP 20 amp breakers (Square D Homeline) is only $60.00. In that case, the customers are getting a main breaker whether they need it or not.

Thanks folks, that clears that up.....John