-->Did I choose a stinker of a card?<---
Yes, it's a stinker. Return it if you can. It'll be loud, use more power than needed, and Lightroom 4 doesn't use any gpu acceleration.
Photoshop does, and it's based on Open CL and Open GL (not CUDA), so you can use Intel, AMD, or Nvidia to get the benefit. Premiere is the app that historically used CUDA..and it is also moving to Open CL and GL. The caveat is some Photoshop plug-ins use CUDA.
So, if you don't use CUDA-enabled photoshop plug-ins, then try a build w/o a discrete GPU. If it seems sluggish, then add a current generation (HD7xxx or GTX 6xx) $100 gpu with 512MB to 1GB of RAM. I haven't found a benchmark test yet that shows gpu horsepower vs speed improvement comparing the iGP vs discrete GPU. But, I don't think you need a high powered gaming card for this.
Case: I haven't read Puget's qual test. I can understand why a shipper wouldn't like the Solo's suspended drives. But, you won't have UPS monkeys turning your case upside down. In practice, the suspension can be tightened enough to hold the drives in place. Or, you can use the standard mounts. If you don't like the Solo II, there's a variety of quiet cases. Here's a laundry list: The P183 and
P280,
Corsair 550D,
Fractal Design Define R3, Silverstone
FT02. Oops, forgot about your depth requirement - R3 and Arc Midi would be the two I'd prefer.
Build noise: It can easily be quieter than the HP with the right components.