Hi 51cent, thanks for all that, that's a great help. I just didn't know what the quality of that kind of camera would be. If it's bad then I won't bother, it just looked at a quick glance like it might fit neatly into something non-camera looking. I'd rather have good quality but can't really afford to massively splash out.
The reason for the IR light being different is just the physicality of my front door as it's a bit weird. I'd rather have them lit from the front with the camera to the side, instead of both being to one side.
Thanks again for your help, I'm still looking at various options. I wish I had run some more Cat5 cables under my floor as I only had it laid about 18 months ago. I think hardwiring the cameras in now would be a massive pain.