300 gal advice

[FishyFishy!]

I would probably look into adding more rock for biological filtration with a tank that size.

I think the biggest thing here to give you a recommendation on skimmer is budget!

High Budget - Bubble King
Medium Budget - Nyos Quantum
Average Budget - Reef Octopus, Aquamaxx, Skimz
Tiny Budget - Bubble Magus, Coral Box

IMO you can never go wrong with a good old Reef Octopus classic skimmer. They are priced fairly and work very well. But there are tons of options out there. You can also look for the new line of Maxspect Jump skimmers if you can find them. They seem pretty awesome and are well priced.