I think the studio would be easily the nicest domestic seat. Would be a great selling point on JFK-LAX.
standard Neo layout is 200 seats. Let's wait for more information to come out on Y. The flex cabin on those new A321NEO allows for more seats to be squeezed in. I would not be surprised if the domestic one ends up being 162 or 165 seats instead of 159 seats on mint 1.0. For LR, I think they are probably going to be 138 total seat is possible. Although my guess is 140 to 145.