Nice pic- once you figure out it's sideways
That's a perfect application for an "all in one" panel. The existing meter base is only rated for 60 amps, and the new service will have to be at least 100 amps.
The mast might be a problem. I would hope you can relocate the drop, and punch the new mast straight through the eave. Here's where you pay extra-close attention to your PoCo specs; they often specify the drop has to be within a certain distance of the corner of the house.
Don't forget to add ground rods; that service most likely has only a water bond.
