Wouldn't the p7300 be a little large also? (8.9")
If i had to choose i would go with the p7300 galaxy tab.
P7300 is rocking a dual core processor plus 3.0 honeycomb.
p1000 is operating 2.3 Gingerbread ( i think) with an older processor.

As far the carriers in the states,it's going to depend on where you live!
T-mobile has better pricing while Att is going to have better coverage.