PWM Fan and XP-120 on Asus P5AD2 Prem

I am a newbie to overclocking and have 2 questions:

1: Does anyone have a source for PWM fans, I have an Intel LGA775 Prescott 3.4G CPU. The stock cooler uses a 4 wire PWM fan. I want to upgrade the cooler to the Thermalright XP120 or XP90 and would like to use a PWM Fan. I found JMC, but no place to order.

2: Has any one tried the Thermalright XP120 on the Asus P5AD2 Premium MB? Given the size of this cooler I am a bit worried about it fitting.

Thanks for the feedback.