So heres some pics of my current setup. I get really good temps and its real quiet.
Here I cut 3 - 3" holes on the floor of the case. I used a 3" circular drill bit, the kind used to install door knobs. It was real fast. The case is raised off the floor with wheels. As you can see, i could care less about dust.
This big hole in the back was where I had 2 80m exhaust fans mounted. I removed them and remounted them elswhere. The whole is left as is, yes its a big hole. For the PSU fan i removed it and the remounted it backwards so it sucks air in. This is so it get cool air from outside. Also the PSU is mounted upside down. The air blown into the case is expelled upwards directly towards the exhaust fans.
Here are the fans final resting place. On top blowing air out of the case. Heat rises so this in my opinion is the best way to expell air. I have the fans running at 5v. I normally would have used my 3" drill bit to cut 4 holes instead of fabricating this plexi glass mount, but there was a vent thing on the top of the case right where i wanted the holes to be.
Heres where the 2 front fans used to be.
A large view of the side.