Questions - Need some input

Hello, I'm looking purchase one of these three protein skimmers.

I have a 90gal. with medium bio-load. I do tend to over feed a little.

1. Reef octopus 4
2. SWC extreme 160 cone
3. Bubble Magus BM-NAC7 cone.

Which one is the easiest to adjust and does one last longer than the other as far as the pump goes.

Any suggestions would be very helpful.

Thanks.

Hello, what is the difference between GFO and Biopellets.