Avoid the Behringer gear, you can find better if you buy used.
Take a look at
the DBX 166 series of compressors. There's the original 166, the 166A, and
the 166XL. You could get any of those for around $150 more or less on eBay. I used to own a 166A and it's built solidly and has an internal power supply. Definitely a cut or two or three above Behringer gear.
Some of the older DBX compressors like the 117, 118, and 119 are selling for considerably under $100. Those models are all stereo, but you could afford to get two of them.
Another option is the Alesis CLX-440. It's a little more than your budget, but is under $200. It is four channel (dual stereo). I've not heard one, but would be worth consideration at your budget level.
I'd suggest
the TC Electronic Triple C, but that's above your budget as well. You'd have a lot more options available if you even saved up $250-300 versus $100-150.
Anyway, a used DBX 166/166A/166XL is the way I personally would go if I had your budget and need for two independent channels of compression. And I'd try to find them in that order: original 166 in great condition first, then the 166A, and lastly the 166XL. The originals in great shape seem to often go for more money, so you'd probably end up with a 166A or 166XL.
Hope this helps.