The top one is the best one. I've not used the 4MP Dahuas yet but I've got a
Dahua HDW-4300C from here and it's amazing at night.
Here are some night videos of the
Dahua HDW-4300S (similar to bottom one) and the quality of this one is good too. I don't have them side-by-side or I'd make my own video to post here. I'm not sure why they haven't got night videos of the 4300C, next time I order something I'll mention it.
From my experience Dahua > Hikvision at night.
Agree with fenderman (again)... 30m, you'll need PTZ with a good sensor. I've got this
2MP PTZ connected to my Hikvision NVR and it's good for 50m, but as you can see from the video, it's not magic good (nothing will be), it's good versus a normal camera. The adaptive IR is great... at first I thought 2 LEDs on it were broken until I zoomed in!
I'm in the UK though... if you're in the US then best to see what
@milkisbad has got. Most people don't need 30m and I'd say his new 4MP DS-2CD2332 equivalent (similar to your top ones) will be great for 99% of people.
Btw, IR array is not always better than IR LEDs and there are other factors involved, like the sensor etc which make a big difference in low-light conditions.