I highly recommend the new Sightmark Photon RT, it is definitely going to be your best bang for your buck on a budget. It is the 3rd generation of the Photon models and it's a great upgrade with lots of cool features like video recording and a super bright IR illuminator that will let you see out to 250 yards. I really don't see how you can go wrong and there is nothing on the market any better for under $1,000.
I just shot a couple review videos on the Photon RT's. Here is the full (very long) review but I really explain the differences in the models and what they will and won't do.
Let me know if you have any questions.
- Jason