Boo Yes said:
My motherboard is the ASUS P8H77-M PRO.
Nothing unusual about that board. You can use any ATX12V / EPS12V PSU available. http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007657%20600014006&IsNodeId=1&name=ATX12V%20%2f%20EPS12V&Order=RATING
PSUs today are vary standardized, as are motherboards. If you would like to get an idea of the size, use one of the PSU calculators available: http://www.thermaltake.outervision.com/
Good brands are Seasonic, Corsair, Antec, XFX, PC Power and Cooling, and most Rosewills.