Vortex
Someone already recommended the Strikefire so I will mention the SPARC. I picked one up from PSA about a month ago for $150 plus free shipping (I think the price has gone down since I ordered). So far a great little optic. Holds zero, small(ish) dot and nice and small. Plus I hear the Vortex customer service and warranty is top notch. It came with all the different mounts to get any height you want out of it. I've got it mounted at absolute cowitness and its perfect for me. It came with 2 batteries, I'm still on my first, but I hear that they are expensive to replace.
Good luck on your search!