Just get a new arcade unit. You will always get the newest chipset. Because they have the memory card built in now, and not external, and every 360 with the built in card is the newest chipset. It would almost be impossible to find an arcade actually for sale, that was new, and didn't have the newest chipset. Buy the arcade and upgrade. Best option.

Changing the DVD drive mechanism should have reduced a fair amount of the Xbox360 noise. The BenQ drives were supposedly quieter than the originals and the current Lite-Ons are supposedly even quieter.

As for the internal fans, I could definitely hear them humming away in the Zephyr (an oscillating, whining hum). Definitely the source of most of the noise coming from the console, on idle or even while running games.

I'm sure that was a big source of noise reduction with the Falcons due to lower wattage requirements, lower power requirements, less heat and slower/quieter fan speeds.

Jasper uses even less power, meaning less heat and even quieter fan speeds.

It's too bad I won't be replacing my 360 any time soon because they are unquestionably better pieces of hardware currently. But the odds of me seeing a RRoD/E74 failure are extremely low for the simple reason that a console can't die from overheating/overuse when it only sees minimal use.