P5W DH Deluxe

I have this weird issue with this board where after I shut down the pc and want to power it on again, the pc doesn't boot the first time but it does the second time. This is a consistent behaviour and it's really annoying XD P.S. I don't think the age of the board matters as I've used many...

Z77 extreme 4 and a thermaltake commander MS-I Epic edition tower that supports standard PS2 PSU's? I want at least a 750w, up to 1000w right around $130. I just need a suggestion for reliability, SLI ready and one that will fit in the case properly. Thanks guys