So the cheap and cheerful evilbay fans arrived and were fitted to my Ohm Decade box. Running in pushmepullyou style to avoid Swiss cheesing the case lest their be whining from the peanut gallery
edit also note the use of only 2 screws on the fans to stop @mnementh having another dig
Ran it up without heatsink paste for interest and it ran over 20C hotter without it.
Testing was done with 1,2,3,4
resistors in parallel for a measured 0.484
off my milliohm meter with 4W. (runs 1A test current)
Ran it up to 10A and the peak Temp was 35C against an ambient of 22C for 0.486
Increased to theoretical maximum of 50W across the 1 ohm at and still got a reading of 0.486
and a max temp of 48C. (100W+) after 10+ minutes of use.
Nice flat Tempco it seems and the fans and heatsinks are overkill but I guess if I needed to it would certainly handle a chunk more before the smoke came out