I dont think replacing those artic cooler fans is going to do anything for preventing those caps or VRMs from burning out. Maybe adding or reorienting case fans may help if those components are overheating (are they?)
I was thinking to replace them by some BitFenix Spectre PRO PWM 140 mm :
http://www.bitfenix.com/global/en/products/accessories/spectre-pro-pwm#specsAir Flow (CFM) 122.2 CFM
Noise (dB-A) 29.2 dB(A)
Maybe this one:
Yate Loon D14SH-12, 140x140x25mm, 2800rpm, 237.8m³/h, 48.5dB(A)