The 24-pin is the main power connector for the mobo, the 8-pin is for the CPU. Your cpu's heatsink/fan will have a 4 or 8 pin connector on it to mate with this 8-pin 12V connector on the mobo.
The 12V connector would be relevant for the CPU you buy to go with it, not the power supply.
Corsair builder and enthusiast series are the best options for your wattage range, and good quality. Many folks think the best thing to is get a GOOD power supply - like a Corsair, instead of a cheaply-made, less expensive alternative.
CPU HSF has a 4 pin fan connector, can't connect it to the 8 pin 12v connector
Don't need any more confusion http://www.playtool.com/pages/psuconnectors/connectors.html