Most fans are under 1 watt, let alone 7, so unless you have an ungodly number of fans in your case, 30W/channel should be more than adequate. I could see 60W/channel if you want to put lights or big pumps on a channel...
Either way it would be nice to get more/cheaper 6-channel controllers. I have seen a number of power supplies recently that did still have the floppy connector, so I guess it can finally get some use again. The design though just doesn't strike me as all that eye catching.