If the ram was holding you back, how are you cooling it now? From the pics it appears that you don't have any ramsinks at all. Just the one big one on the gpu.
Since you have the milling machine, you should try a project I've been thinking of for a while. If you can get some blocks of aluminum, you could measure the size required to attach large heatsinks to the ram chips. Basically have 2 large "L" shaped heatsinks that only touch on the ram chips. You could use your milling machine to trim down the aluminum in places that other components would stick up in the way.
Also, I wonder if it would help if you mounted the 80mm fan "above" the card, that way the dead spot under the center of the fan isn't directly on top of your heatsink. Also, the fan is so close to your sound card that it seems like it won't pull much air. Having the card right there may also cause unwanted noise, due to the way the air is flowing through.
BTW: very nice work. I like it!
