The original system wasn't tuned for silence: I bolted that idea on after the fact with a new PSU, fan selections, SSD, etc, and despite the lack of silencing features it has actually turned out really well. That is something I hadn't though of, though. If it turns out my GTX is still too noisy even after tuning it up, a quieter case might be something to consider as opposed to a quieter GPU (since I still don't really have any guarantee a newer card would be quieter, although it stands to reason it would be if the power requirements and heat output on a new one are greatly reduced for the same load).
As discussed here though, it does appear the GTX is getting way hotter than it should be, so we'll see. I finished cleaning it out but still need to re-thermal-paste and reassemble. Doing this all in 5 minute breaks every half hour or so with a 20 min break coming up where I should be able to get it all back together.
