Here is the pump I got for my system.
Aquarium Water Circulation and Water Pumps: Taam Rio® HyperFlow
I also looked at the mag drives but was unwilling to fork over $150 or more for a pump. lol They do come highly rated though.
My plan is to have a backup return pump since I got a cheaper one. Still will come out less than a mag drive. I already have a pump that'll run a few hundred gph
in case of an immediate need though.
As far as a skimmer. I would say wait a bit until everything has come together before adding one. It's a must in my opinion if you plan on keeping corals but for the fish only thing it's just an added bonus to have.
Were you making the sump yourself? This thread has me confused and I forgot what you decided. lol
Either way, I would window shop skimmers now to see their dimensions. You dont' wanna get a sump put together only to find the skimmer you planned on doesn't fit. My skimmer goes in kinda sideways but does actually fit. For the most part anyway.
Hope that helps a bit.