New power supply should help alot your system has the newer processor Im running the 920 and im guessing you have 2 four prong plugs by your processor and only one has power so your not really getting full power to it . When I bought mine I came home with a bigger ps I have a 700w might be why I havent had some of the errors others have had. Any matx motherboard should fit. I like the Asus rampage gene II the best and the Evga one isnt bad either they seem to have the most options and are user friendly as far as overclocking. If you change go for the one that has the options your looking for.