You might want to check out the Holosun HS510C Circle Dot Open Reflex Sight. More compact than the EoTech but has a similar look. Also has some nice features like solar/battery power and three reticle options (dot, circle & circle dot). Dot is slightly larger than the EoTech (2 MOA vs. 1 MOA) but you probably won't notice the difference. Might be a little higher than your budget (mid-$450 range) but they get great reviews and the Holosun warranty is good. I picked one up from SRS Tactical (great to deal with BTW) when they had a 10% off sale so cost just over $400. There is also a green dot version for about $40 more.