I don’t have the time to provide full details at this point, so here’s the simple version:
The Noctua NH-C12P is incompatible in numerous ways with an Antec P182 case, and equally as incompatible with Asus P5Q SE and Asus P5Q SE/R motherboards (despite Noctua stating otherwise on their site).
I have videos documenting the problems, but need time to do a full write-up as well as edit the videos + upload them to WordPress.
Buyer beware: if you’re looking for a good heat sink for your new Asus P5Q SE board, or wanting to upgrade to a new sink while using an Antec P182, avoid the NH-C12P.
I have no idea if the NH-U12P will work, but based on the similarities to the NH-C12P, I would have to say no, it probably won’t work.