You didn't specify which birds you'd be hunting, but if you're talking about upland bird, be aware that one gun probably won't be ideal for your hunting needs and clay target needs.
Lighter guns are nice for upland hunting when you're doing more walking than shooting. On the other hand, more weight is often preferred for clay targets.
In pumps, I'd choose a Remington 870 over the 887. Good or bad, the Benelli Nova is noticeably heavier than the 870.
As for semi-autos, I'd give the Mossberg 930 a good look if I wanted to keep costs a little lower. A lot of people consider them very good values.