Hi,
Are you sure you want IP? You can get a HD Analogue system for so much cheaper, and get the DVR networked so that it can be viewed online and on your mobile phone.
www.cctvdirect.co.uk do HD kits - and provide a service to connect your DVR to the internet, and then you access your images from anywhere. Also have a choice of cameras on those kits so you could choose the best - I'm sure they could also mix and match different cameras if that would suit you better.
Hope this helps