Totally understood- the Michelins are a solid choice. They basically set the bar. After them I'd choose the conti's. The difference below the Michelin's just boils down to preference.
You're spot on with the 18 v 19 inch argument. As for widths and offsets that's probably for a separate thread to see what works for others (in terms of clearances/looks/stance and potential damage). There won't be any performance difference.
I took a look at the calendar for average temps by you (ignoring rain and snow) and there are really only 2 months you could safely use a summer tire, July and August. Jan Feb March April are too cold, June and Sept you are on the fence (since average means some days will still be too cold), then October November and December are too cold again.
Even if you don't drive on the summer tires, when you aren't using them you can't even store them in low temps, they need to stay warm/pliable (per the manufacturer). Preferably in the living room, in front of the fireplace, ideally on the couch.
If you don't mind swapping out your tires, and you never have true snow, just colder temps than the summers can handle, you can put the all season version of your Michelin for the 'winter' months and then swap for summers for your 8 weeks of 'summer'.
(I chuckle where I see places that have summers below 90 degrees
)
Now mathematically/financially most people put their 'winters' on their stock wheels. Especially when it snows since smaller rim and narrower rubber is a performance boost in the slush. But since your 'winter' is most of the year, you will want to have your sexy wheels year round, and you can either mount/unmount on the same set, or have two sets of rims $$$
I only say this because to me it seems counter intuitive to get a summer tire because it grips the best, only to use it in months where the temperature they operate in actively removes all the grip I paid for. That and the tires will tear themselves apart in cold temps as they turn to plastic in their "glass transition."
If it was my money, since you aren't concerned with noise or ride, I'd get the grippiest cost no object tire that fits the nicest 18" rim of the width that I like - which still works in sub 40 degree weather (which is only 4 weeks away) -and see how I like it.
If the performance is still lacking, then when it warms up again next June move to a dedicated summer tire.
Seth