Any tips for quiet side panel ventilation/cooling?

[XtalMan]

Hi everyone,

I've been lurking for a long time, and used the advice here to quiet my system. Now, I'm going to upgrade and use the spare parts to build a HTPC based on MythTV . I wasn't able to find a satisfactory (read, cheap) desktop-style case that I liked for a reasonable price, so now I'm going to hide a mid-tower inside my entertainment center. This will completely block the front vent, top, bottom, and one side of the case. That leaves one side and the back open. What is the quietest option that will allow reasonable cooling for my system?

Current system gives Case/CPU temps of 32/56 when folding:
Antec Mid Tower Case
Antec SL350 - removed 92mm fan, 80mm Panaflo L1A exhaust @ 12V
80mm Panaflo L1A case fan @ 7V
AMD Duron 1.1 with retail HS, 80mm Panaflo L1A w/60-80mm adapter
Geforce2 MX400
ECS K7S5A mobo
Maxtor D740 80Gb 7200 RPM 2Mb cache HD

I'm going to recycle many of these parts into a HTPC:
Chenbro Jasper Case (see pictures) Only $29, fits almost perfectly into the side DVD/CD shelf of my el cheapo entertainment center
Fortron 300 Watt PS
80mm Panaflo L1A case fan @ 7V
AMD Duron 1.1 with retail HS, 80mm Panaflo L1A w/60-80mm adapter
Geforce2 MX400
ECS K7S5A mobo
6.4 Gb 4200 rpm Laptop HD (always on)
160 Gb Samsung Spinpoint 5400 RPM 2Mb cache HD (powered down when not recording)

I think the PS and case fan will exhaust from the back pretty well. The front case vents will be completely blocked, though.

I'm considering four options right now.
(1) Cut a big hole in the side panel, and cover with modder's mesh. I'm worried about noise, though. If I take the side panel off my current PC, temps drop 4 degrees, but I can hear the 12V CPU fan and hard drive seeks very well.

(2) Put a [80mm|92mm|120mm] fan in the side, blowing directly onto the CPU. Maybe even remove the 80mm fan/60mm adapter kludge. The case is not very wide, so the fan should be pretty close to the heat sink. Does distance from the fan to heat-sink affect CPU temps much? If I offset the fan, I should be able to keep the heat sink out of the "dead spot". Again, I'm worried about the noise factor. Also, this configuration wouldn't circulate air to the hard drives very well.

(3) Mount a [80mm|92mm|120mm] fan blowing on the CPU, and a [80mm|92mm|120mm] fan blowing on the drive bays. I have 80mm Panaflo L1A on hand, so I'd probably try those first. I don't know if there's enough space for a fan next to the drive bays, though. Maybe a vent instead, if the hard drives are quiet.

(4) Cut a port in the bottom of the case and another through the floor of the entertainment center. Maybe aid it with an intake fan.

Any other suggestions? I'm not sure if I'm worrying too much about HD heat. If I tackle these options in the right order, I'll only have to destroy 1 side panel.