Hello again!
Oli: The capacitor problems is common, but we can not really solve it. If it is about the small chance, that they stick out more than usual. We would need to put all the LGA775 Mobos to "not compatible"
The chances are that it does not fit, but this is why we have the Universal Retention Kit has the copper spacer ^^
Slizer: Gigabyte x38-DS4 is really difficult to say. They seem to use a different heatsink and I would need to order that mobo from them, to check that. The height is the factor which might cause incompatibility.
jprokop: ASUS P5N-D 750i SLI looks rather safe. The heatsink is not that tall but wide. Based on what I found on the inet, Mugen and Ninja PLUS both should be fine.
infected: The layout looks safe. I can not locate any issues, even with Universal Retention Kit it should be OK.