If you want an aftermarket cooler, the Hyper 212 EVO is more than enough. You can even go stock if you want.
Also, don't buy an itx case with a pre-installed power supply. Get something like the Cooler Master 110, 120, or 130 and then buy an EVGA power supply.
PCPartPicker part list / Price breakdown by merchant
CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor ($62.99 @ Amazon)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.99 @ SuperBiiz)
Motherboard: Gigabyte GA-H97N-WIFI Mini ITX LGA1150 Motherboard ($114.99 @ SuperBiiz)
Memory: G.Skill Ripjaws X Series 4GB (2 x 2GB) DDR3-1600 Memory ($39.89 @ OutletPC)
Storage: Crucial MX100 128GB 2.5" Solid State Drive ($62.99 @ Amazon)
Video Card: Asus GeForce GTX 550 Ti 1GB Video Card
Power Supply: EVGA 430W 80+ Certified ATX Power Supply ($33.89 @ OutletPC)
Other: Cooler Master 130 Mini ITX Cube Case ($49.99)
Total: $394.73
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-22 18:01 EST-0500
Take of $30 if you don't want the 212 EVO. That will make it $365 in total.
Also, don't buy an itx case with a pre-installed power supply. Get something like the Cooler Master 110, 120, or 130 and then buy an EVGA power supply.
PCPartPicker part list / Price breakdown by merchant
CPU: Intel Pentium G3258 3.2GHz Dual-Core Processor ($62.99 @ Amazon)
CPU Cooler: Cooler Master Hyper 212 EVO 82.9 CFM Sleeve Bearing CPU Cooler ($29.99 @ SuperBiiz)
Motherboard: Gigabyte GA-H97N-WIFI Mini ITX LGA1150 Motherboard ($114.99 @ SuperBiiz)
Memory: G.Skill Ripjaws X Series 4GB (2 x 2GB) DDR3-1600 Memory ($39.89 @ OutletPC)
Storage: Crucial MX100 128GB 2.5" Solid State Drive ($62.99 @ Amazon)
Video Card: Asus GeForce GTX 550 Ti 1GB Video Card
Power Supply: EVGA 430W 80+ Certified ATX Power Supply ($33.89 @ OutletPC)
Other: Cooler Master 130 Mini ITX Cube Case ($49.99)
Total: $394.73
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-02-22 18:01 EST-0500
Take of $30 if you don't want the 212 EVO. That will make it $365 in total.