NH L9I is well documented. Max CPU Cooler Height 37 mmFan Dimensions 92 x 92 x 14 mmHeatsink Dimensions 23 x 95 x 95 mm [URL] [URL]   [URL] NH-L9 stands a mere 37mm tall NH-L9i has a 95x95mm footprint [URL]    
I'm looking for a compatible fan for Alienware X51, itx and small enough to fit in the case. From what I read Noctua NH-l9i is the one unfortunately its not available where I live, its confusing I spent hours looking for the right dimensions then I read somewhere that it needs a fan that pushes the air away, wondering if I can get one that I can flip both sides while being small enough to fit in the case with heatsink. currently I have Noctua, dont know the model. Are intel 1155 fans compatible with all 1155 sockets meaning do they screws all line up and should technically fit.  Any rec would be helpful.
X51 R?, fan