Aftermarket heatsink that fits Dell T3500? Fitment?

[gryffinwings]

I'm looking at replacing the stock heatsink with something a bit better. The one I'm looking at seems like it will fit, but it's hard to tell. Looking at the BeQuiet! Dark Rock Pro 4 or just the Dark Rock 4. Would one of these fit?

Any other options?

 

[gryffinwings]

So, I did a little test fitting to see how much space I have in regards to width with a 120mm fan I had sitting around, and it seems to be a very tight fit, so I don't think the Be Quiet! Solutions will work that well. I was doing some research and came across the Noctua coolers for LGA 1366 workstation coolers, here's links to Noctua's pages for specifics:

Noctua NH-D9DX i4 (110mm height, 95mm x 95mm)
https://noctua.at/en/products/cpu-cooler-workstation-server/nh-d9dx-i4-3u

Noctua NH-U9DX i4 (125mm height, 95mm x 95mm)
https://noctua.at/en/products/cpu-cooler-workstation-server/nh-u9dx-i4

Would there be any reason to go for one or the other? I was thinking maybe the shorter one would fit a bit better in my particular application. The only thing not specified is the TDP of each cooler. Thoughts?

Here's a picture of the motherboard both inside and outside the case.