As far as seniority, it is hard to say with all the surplus bumps going on right now.
However, HNL (rumored to be closing) is ultra senior with only about 20 or so pilots (not crews, total pilots) based there. SEA is also pretty senior. Other than those two, I'm not sure anymore about seniority.
The domiciles are as follows:
HNL - 747
SEA - 777, 767/757, 737
SFO - 747, 777, 767/757, 737, A320
LAX - same equipment as SFO
DEN - same as SFO except 747 and 777
ORD - same as SFO
JFK - not sure about equipment (too lazy to look it up)
IAD (Dulles) - 737, and not sure on other equipment
MIA - 767/757, not sure about other equipment