I'm using this case:
http://www.newegg.com/Product/...3&Tpk=Rosewill%20R5605
and a m-ATX motherboard. The PSU is an OCZ 700W MXSP.
I have a bolt thru kit, and considered turning the heatsink 90 degrees, but then the fan would be blowing hot air right into the PSU. The heatsink makes contact with the grill on the PSU about 3/8 in. off of where the motherboard should allign with the mounting holes. I forced it the first time I installed everything, but I'm not comfortable leaving it like that. It was visibly bending the heatsink down, and stressing the motherboard.
I decided to give this heatsink a try after comparing the dimensions:
http://www.newegg.com/Product/...x?Item=N82E16835200026
Even though the SD964 is $2 cheaper after MIR, I would still have to buy another bracket + the cost of shipping.
My temps according to HWMonitor and Speedfan were around 36-40C idle while I had the S1283 installed, on a stock E5200. Seems high to me, and I was thinking it's because the heatsink wouldn't fit properly. My room stays around 68-70F.