Well I can't help you with everything, but I would definately say go for as many titans as you can as they are the fastest single GPU cards out there at the moment, and seeing as you want to run 6 3D monitors I'd imagine you will need the horsepower. Also what resolution do you want to run the monitors. I don't know much about monitors so hopefully someone else can help you.
As for the RAM, if I'm correct, Corsair just released a kit with ridiculously high frequency, something like 3200 mhz. You could get 32 gigs of that.
This bit is just personal preference, but for me I think completely transparent cases look awful because you can see all the wires no matter where you hide them. Personally I would go for a Caselabs case, as they make insane cases with so much water cooling potential and they are massive, so you might want to look into that, but again, it's personal preference so if you want a clear case, go for it, although I don't know measurements and stuff, but I'd imagine it would need to be pretty huge for all the stuff you want.
About the PCI storage, I remember seeing that Asus has something like this coming out because I saw it as CES. I don't know if it's out yet though so you could abit of research there. I know for a fact that techoftommorow covered it at CES, not sure if Linus did though.
Sorry I couldn't be of more help. Good luck!