Are you dead set on going polymer? I've heard of the Magpul polymer sights breaking during installation. Probably due to over-tightening, but you get the idea. I'm a big fan of the Troy battle sights. Also, check GG&G and Midwest.
What makes the green grass grow? BLOOD, BLOOD, BRIGHT RED BLOOD!
Whose blood? THE BLOOD OF MY ENEMIES!
What is the spirit of the bayonet? TO KILL, KILL, KILL WITHOUT MERCY!