Simple universal E3d double fan cooler
Hopefully this will fit most printers. The heat sink mount snaps on and will hold a 30mm fan. A 40mm fan is needed for the duct.
Right now I am using this on my RostockMax without stand offs.
a couple of nuts are needed to mount the duct fan, I plan on changing this to make it simpler.
UPDATE
Version two doesn't require nuts, simply thread the holes to mount. Also, I've lowered the arms to give more clearance for larger fans.