Advice for Noctua heatsink

I'm putting together a pc with these partial components:
Lian-Li pc-7A plus - depth 210mm
Asus M2N-E
AMD Athlon 64 x2 dual 5200+
heatsink Noctua:
- NH-U9F 92mm fan, HxWxD: 128x95x95mm
or
- NH-U12F 120mm, HxWxD: 155x125x95mm

my doubt, before i buy the hs, if i can easily insert the 155mm high one
or i'd better stick with the NH-U9F.
Pc for uffice work, video-editing & no gaming.
thanks for your views & ciao,
Genri