as for a skimmer, the octopus skimmers have been getting good reviews from some members here. they're a needle wheel design and not much money. look at the octopus NW-150 for your tank.
the best choice for a return pump is going to depend on wether you want an external pump or submersible. a lot of people use Mag pumps for their returns, as have I, and with no real complaints as long as you don't go above a Mag12. anything bigger than that (Mag18,24, or 36) and virtually everyone complains about how noisy they are. a Mag9.5 or Mag12 would probably be a good bet for a 90gal. external pumps to look at might be the blueline, iwaki, or poseidon pumps.