Another good skimmer I wouldn't hesitate buying is the ATB. Just bought a ATB return pump and Victors(ATB)customer service is awesome!

The Bubble King Super Marine 250 ($1800) would be king in this competition. However, not everyone can afford an $1800 skimmer. So there are some cheaper versions that are comparable in design as far as flow and air intake. Obviously there are sacrifices made to produce a cheaper skimmer like pump quality and build quality. Most of the better skimmers are essentially all designed the same (main difference being cylindrical or conical)...it's not hard to make copycats. The Bubble King is an industry leader right now, and is the Rolls Royce of skimmers. It will outperform other skimmers in its size class.

In the same size class are the Vertex Alpha Cone 250 ($1200), the Skimz 251 ($750), and the SWC 230 cone ($565).

A 300 gallon saltwater tank is a big jump to make as a newbie, and not something I would personally recommend mostly because of costs associated with setup and maintenance as well as little mistakes turn into large costly mistakes very quickly. If a hobby is costing a person a lot of money, and is not pleasing or satisfying to partake in loss of interest quickly ensues. I believe a newbie is better off starting with a budget, and then choose a tank size to appropriately match. Many newbies get turned off of reefing because they buy sub-par equipment which makes maintenance much more difficult and the tank slowly dwindles into a slough. I think the biggest mistake a newbie can make is skimping out on a skimmer. A good skimmer will help to buffer many newbie mistakes, a so-so skimmer will not absorb newbie mistakes.

I don't know anything about those Bubble Magnus (isn't it Magus?). I heard a lot of talk about them 1-2 years ago, but haven't heard much talk lately.

That used Bubble King I PMed you about sold on Thursday. :(

Yup i spoke to him yesterday and he said it was sold before he shut it down lol. But thanks for the help :)
Ive seen a few videos of larger setups and they seem to be going with the taller inline skimmers or the ASM G4+ but that may not fit as I will only have a half inch of play ontop of the cup.

Oh that's weird, it was sitting in the store for like 3 weeks.

You need at least 1" to be safe that you can get that cup out of there. Try cutting a stick the exact height of the skimmer and put it in your sump to double check height. Sometimes we don't measure properly when we have glass thicknesses and such at play.