I'd go full.
I knocked down a coyote with 3" 00 buck at 90-100 yards last week with my mossbeg 395 (fixed full choke). Dropped like a rock and was dead when I got there.
You'll get alot more range out of a full choke (or tighter) than a mod. Just don't constrict too much if your using bigger shot or it might affect your patterns.
What shot size are you using?