Streaming with a USB webcam...Sunlight, focus, gain, exposure

[TJKLECKNER]

I need a good, but very basic webcam for streaming on SevereStudios. I will use Flash Media Live Encoder 3.2. I'm not going for high bit rate, but I need something that will look decent. The computer I'm using is my old Vista laptop, so the webcam can't be heavy on the resources. The camera has to have decent focus and automatic gain/exposure for when I'm going between rain/clouds and bright sunlight. I won't be streaming very often, but when I do stream, I don't want it to look like crap. I'm afraid to buy a camera without some reviews from someone that has used them before. A few cameras that I have seen mentioned on here before:

Microsoft LifeCam HD-5000
Microsoft LifeCam HD-5000s
Logitech HD Webcam