Mason
I have mess whith a lot of skimmer and ended with only one conclusion
pound to pound they mosly are equal and whith a 120 you beter buy right at first or you will end
buying twice
Like titus said a couter curent could blown away
a becket skimer but you will need more than a 75$ air pumps to do it so that why I recomend you a becket skimer run with a mag 18 then you will have the best for your $ IMO
Here a couple of good link on skimmer knowlege
http://www.reefcentral.com/vbulletin...ghlight=becket
http://www.reefcentral.com/vbulletin...t&pagenumber=1
hope this help!!!