butler creek flip ups are your best bang for the buck, most stores stock them and the catalog / mail order places defiantly stock them, they are usually $10 per side and make sure to order them when you order the scope because fitting them after the fact is a pain unless you bring the rifle to the gun store. (Sizing them is a problem for me.... easier to take gun with me)
Butler creeks can be had in see thru or solid black flip ups..... I suggest the solid black ones unless a super quick un prepared for shot is neccesary....
if you really want to spend money Leupold has brand name flip ups to now but they run over $60 a pair.