Another small update: my fans from PPC arrived. I got three medium speed slipstreams to undervolt and use as case fans. I think the PWM slipstream on the heatsink is too loud, so I also ordered an Arctic Cooling F12 PWM. Two of the medium speed slipstreams are run off of the 5v rail as exhausts and are dead silent. The F12 feels a bit cheaper in construction than the slipstreams, but it is much quieter than the slipstream PWM that it replaced. Plus it has a fluid dynamic bearing that should be able to handle heat and horizontal mounting without a problem. Here is the third slipstream with a grille to protect fingers/cats. Actually getting it in place was just a matter of tipping the rack forward and sliding the fan down. This one is run at 7v to keep the hard drives cool. It is audible, but quiet. Since it is at the rear of the case, it won't be heard. It moves a fair bit of air, even with the wall of hard drives directly behind it. Everything fits together nicely. The only thing I don't care for is the bundle of wire next to the power supply. Most of this is unnecessary cabling that I could probably just cut off. However, the last time I trimmed down a power supply, I regretted it later when I wanted to repurpose the supply. I may just construct a small metal panel to cover the bundle.