You might want to consider some typhoon's insted, if you need more air pressure 
I heard about them, but I couldn't source them easily.
Noctua are 1200 rpm ; are the Typhoons really more effective ?
go commercial or server grade is better.
i use the Delta and sanace 92mm fans.... you really need those 3000-5000rpm fans to get things moving. of coz sound levels will suffer more..
btw, your perforated steel case looks great..
