-> the store I work at puts together 'ice boxes' where you have maybe for or five fans in the box and you can throw in a nice copper cpu heatsink/fan. If you like that, go with it, man, and get the full-blown cpu water cooling setup.

-> all kidding aside, your lucky to have made it like that for two years, imo, because I've lost more than one component to heat.

-> as far as whether the fans should pull warmer or cooler air over the system, I would guess that the manufacturers would recommend cooler air. increased heat=increased resistance in electronic components, and if you want billions of cycles in the processor you want as little resistance as possible on not just the chipsets but all the many traces all over the board. if you set up fans to work like you suggest (I assume you mean by swapping the power supply as an outlet [high on tower] with the case fan as an inlet [usually lower]), in an enclosed space, the effect would be degraded performance over time.

-> of course, laptops are very densely populated and they do alright in thermal dissipation. let us know how it comes out.