There would be no problem, you will either need to buy a couple of these :
Fan splitter [3$] :
http://www.newegg.com/Product/Product.aspx?Item=N82E16812200855&cm_re=fan_splitter-_-12-200-855-_-Product
or Molex to Fan Adapter (One molex to 4 fans) [6$] :
http://www.newegg.com/Product/Product.aspx?Item=N82E16812311003&cm_re=molex_to_fan-_-12-311-003-_-Product
or if you have money, a fan front panel controller (4 fans) [15$] :
http://www.newegg.com/Product/Product.aspx?Item=N82E16811991006&cm_re=fan_controller-_-11-991-006-_-Product
Your motherboard only supports 2 fans, but coupled with 2 fan splitters, it should be able to support 4.
Use Molex to Fan if you have enough molex connectors, as it doesn't have the risk to overload your motherboard.
300W PSU is more than enough for even couple of big 10W fans.
The front panel controller allows you to control fan speed whenever you want, so if that's your preference, go for it!
Be careful to not connect more than ONE splitter per port on the motherboard. The thin traces on motherboards aren't made to supply huge amount of current!
Tip on using splitters : Never leave a splitter port unused, as the exposed wires can short with your computer case and cause a fun party of burnt plastic and dioxins in your room. Your PSU and motherboard will also be damaged. If you can't use them all, cover it with some electrical resistant tape. (2-3 layers)
Regards,