Aftermarket coolers are much more efficient when it comes to cooling, and keeping the noise down whether you are over clocking or not. An entry level cooler like the Cooler Master Hyper 212 Evo @ $30, would be sufficient for some ambitious overclocks. As for that motherboard question, what is your budget? I have spoiled myself with Asus' ROG line, well-built, awesome VIP customer service, easy RMA's. Perhaps the Asus Crosshairs V Formula @ $220.
Here are a couple links to check out.
Newegg.com - ASUS Crosshair V Formula AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Gaming Motherboard with 3-Way SLI/CrossFireX Support and UEFI BIOS Newegg.com - ASUS Sabertooth 990FX AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard with UEFI BIOS Newegg.com - GIGABYTE GA-990FXA-UD3 AM3+ AMD 990FX SATA 6Gb/s USB 3.0 ATX AMD Motherboard