Welcome to Pro/Cooling!
I take it that watercooling isn't doing it for you!
First, for the fans, you want one that'll give the most flow for the lowest noise. If you search through here, you'll find a link to a chart of many fans, based on their specs. The idea is that regardless of their noise at 12V, the voltage can be adjusted to meet a maximum noise level. The bottom fan is counter-productive: it'll either suck up dust, or disrupt proper flow of air through the case.
Again, look into squirrel cage type blowers.
www.deltaww.com. Most pressure/flow for noise than any of the above.
Ducting the CPU HS helps.
The dynamat should be additional to all the other precautions you've taken to eliminate vibrations throughout the case. You may not need any at all. Think about rubber mounting hard drives. Hot glue those loose 5 1/4 bay plates.
The theory behing the matting is this: if you're trying to block a high frequency noise, you want a solid object (metal plate). To block a low frequency noise, you want soft materials (like the matting).
Good luck, and keep us posted!