I think this one would fit your needs best. Their tactical scopes are good too. You do get what you pay for most of the time when it comes to glass though. I am a firm believer in that. Now what you pay for and what you need are two different things.
Millett Sights - Buck Gold
if you can do 300 id go with the trs-1 (their tactical upper range version) 50mm obj with 30mm tube, mil dot-bar ret. it also has 100 moa of internal adjustment. i think they advertise 70 but i've seen two both with 100. I think its supposed to be built alittle toupher than the buck gold series