Such Thing As Running To Big Of A Skimmer?

[rastaangel]

So im sitting here in my res room bored outta my mind, so im planning all the equpiment ill need when I get home to start workin on starting my 8' 180g build
Right now im looking into what type of skimmer would be good enough to handle the huge bio-load of a tank stocked with almost 2 dozen large angelfish species and have came to the conclusion that my reef octopus xp-2000 cone wont cut the mustard as its only rated up to 180g. I also wanna get a skimmer that can handle a bigger tank when it comes time to go bigger.
I am kinda stuck on the Reef Octopus skimmers cuz I love there bubble blaster pump and gate valve adjustment. I am also considering the vertex alpha cone cuz of its ability to completely tear it down for cleaning but its also double the price...
I am considering the Reef Octopus SRO 5000 and XP-5000 which are both rated for up to 400g, and the Vertex Alpa Cone 250 which is rated for up to 350g.
But my question is am I going to have below average performace using such a large skimmer rated for more then double the system volume I plan to run? Or would it be a good idea to go that big?