ok,
ur board supports the following:
http://ca.asus.com/en/Motherboards/Intel_Socket_1155/P8P67_DELUXE/#CPUS
so basically best bang for the bucks for u would be the 3570k for 220$ ish+a good cooler:
PCPartPicker part list:
http://pcpartpicker.com/p/7vJt
Price breakdown by merchant: http://pcpartpicker.com/p/7vJt/by_merchant/
Benchmarks: http://pcpartpicker.com/p/7vJt/benchmarks/
CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor ($189.99 @ Microcenter)
CPU Cooler: Antec Kuhler H2O 620 Liquid CPU Cooler ($57.99 @ Newegg)
Total: $247.98
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-01-14 15:21 EST-0500)
with water cooling or on air cooling:
PCPartPicker part list:
http://pcpartpicker.com/p/7tGY
Price breakdown by merchant: http://pcpartpicker.com/p/7tGY/by_merchant/
Benchmarks: http://pcpartpicker.com/p/7tGY/benchmarks/
CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor ($189.99 @ Microcenter)
CPU Cooler: Thermaltake CLP0564 101.6 CFM CPU Cooler ($49.99 @ Newegg)
Total: $239.98
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-01-14 15:22 EST-0500)
or for even more performance:
PCPartPicker part list:
http://pcpartpicker.com/p/7EJP
Price breakdown by merchant: http://pcpartpicker.com/p/7EJP/by_merchant/
Benchmarks: http://pcpartpicker.com/p/7EJP/benchmarks/
CPU: Intel Core i5-3570K 3.4GHz Quad-Core Processor ($189.99 @ Microcenter)
CPU Cooler: Thermalright Silver Arrow CPU Cooler ($69.70 @ NCIX US)
Total: $259.69
(Prices include shipping, taxes, and discounts when available.)
(Generated by PCPartPicker 2013-01-14 15:23 EST-0500)
cheers