Aurora R11, how to get a VRM heatsink?

Hello,

I bought a refurbished R11 earlier this year. It came with the air cooler.

Things are fine so far, but I'm considering an upgrade for the fans and CPU cool - the famous H60 solution everyone is talking about. However, I need to install a VRM heatsink, since I would be going from an air-cooled CPU to a AIO liquid cooler (according to many sources, the part number is N1C1D).

Dell Support tells me they can't give me a quote because I bought the system from a third-party (and they couldn't even find the part). I'm still waiting for the seller to get back to me, but I was wondering if anyone had any idea how I could get my hands on the heatsink for a reasonable price.

Thanks!