Be sure to try out red dots before completely writing them off. They work perfectly fine during the day. That's why they have multiple brightness settings.
Aimpoint PRO will be your best bang for the buck as far as unmagnified optics go.
http://www.aimpoint.com/us/products/...w/product/PRO/
They can be had new for under $400.
The main players in the field of unmagnified, professional grade battery powered optics are Aimpoint and EoTech.
If you want something magnified, you will be spending a lot more.