I have owned and extensively experimented with M-Audio Delta 9424, M-Audio Audiophile, M-Audio Delta 410, Delta 1010, STAudio DSP24, Echo Mia, RME DIGI96/8 PAD, RME HDSP 9632, Lynx Two Model B.
I would rate Delta 9624 the weakest and I am now using it in my desktop (reading e-mail and similar activities).
NutGun would be better of buying much cheaper Revolution 7.1 or even better Prodigy 7.1 than Delta9624.
But, the main confusion is that 'the rampant noise' within the PC is somehow going to majorly influence the sound quality, as if the PC sound-card manufacturers are not aware of the operating environment for their products and did not intentionally designed it to compensate for it.
NutGun gives impression of great concern about the sound quality. That being the case RME is choice that will put the mind at rest and let him concentrate on other parts of the audio system where sound can be improved further.
For the reference I now use RME DIGI96/8 PAD connected both by analogue and digital (AES/EBU) to Lexicon MC-12B that is driving a battery of M&K active speakers, 6x2510P, 4x2525P and 2x5310 sub-woofers.
RME produces clearer and more pleasant 2-channel audio than Lexicon can from the same source. Use the correct tool and 'rampant PC noise' does not enter into equation!