I`m looking to buy some fan cantroller, like this zalman multi fan -http://www.newegg.com/Product/Prod [...] 6811999171

Now, my question is should I pay attention to the power supplied to the channels, I saw somewhere someone is worried of 7 watts per channel?

Does it means that my fans won`t be spinning at max speed when I adjust it on controller? Or could he handle them without getting damaged?

I wanted some high rpm and airfllow Skythe ultra kaze or similar...

You mean you read something saying it only outputs 7 watts per channel? If thats the case dont worry about it asides from gigantic fans, checking the manufacturer's web site of the fan's/case with fans should tell you the required power inputs.
Heres an example of a high performance 12cm fan.
http://thermaltakeusa.com/Product. [...] =1725#Tab1
Power Input 2.40 ~ 5.76W
max air flow of 93.7 CFM
that air flow is loud when maxed, but it could blow dry your hair, and as you can see, apparently needs 5.67 watts max

Well, I asked exactly because I was looking for some high CFM ones, like this ULTRA KAZE http://www.scythe-usa.com/product/ [...] etail.html..
and there isn`t any info about power input...

woow :| 133.6 cfm! I would guess you shouldn't have any problems, and wow I want one of those , I thought my fan was the best at ~93cfm, at least mine has a blue led id guess at the very worst case scenario, your fan would be dunked down to 120 cfm max, and for 9 bucks a fan at newegg, id have to say im jealous since I live in canada -.-