I would say the P180, becuase of the seperating chamber it has for the heat of the PS and even some hard drives. I have one and I love it. It keeps all of my stuff real cool and I have all of the fans on low, so I cannot hear my computer at all once it has started up. I have 2 HD's in bottom chamber with the PS and then everything else back up. Moving the HD's left me more room for cable managment so airflow is better. Overall I think both would be good, but I would go with P180...as I did!!!
Best,
3Ball
Antec NeoHE 550w PS
Gigabyte GA-K8N Pro
AMD Athlon 3700+ Sandy - 2.28ghz - "Arctic Freezer 64"
2gb (2x1gb) Patriot Performance Memory (2.5-3-3-5) 415mhz
ATI Original X1900XTX
(2x120gb WD SATA HD's) - Raid 0
Mobo limiting OC!!!