If you are looking at PE, our only options are QF or VA. Both the UA and DL products are not premium economy, they are economy with a couple of inches extra leg room.
I would be inclined towards QF on the A380. You get much more leg room, a wider seat, better recline and almost Business class quality food and drink. That is without mentioning the quieter cabin on the A380. The VA product will also be good but it is on a 773 and I don't know about the specifics of the product.
QF will provide you with a 2 bag allowance. You can buy extra bags in advance for $105 a piece and anything over 50lbs (23kg) is charged at $50.