Konica Minolta Dimage choice

I am looking to upgrade my digital camera. I currently have a Sony Cybershot DSC-S70 which I have had for about 4 years now. It's still a pretty good camera for everyday use but it is limited in as much as it is only a 3 megapixel camera with 3x optical zoom. I would very much like to be able to take wildlife shots including birds and for that I need a far better optical zoom and higher resolution, not to mention faster lapse time between pressing the button and shutter activation. Having researched this for some time I have come to the conclusion that Konica Minolta provide the best options and their cameras have the anti shake system and better optical zoom functionality. Where I am stuck is on deciding which one to go for. Initially I was looking at the Dimage Z3 with 12x optical zoom and 4 megapixels but I think I am more likely to go for either the Dimage A2 or A200. The difference between the latter two in price is about £75 and for features there are pros and cons for both. Quality is a difficult thing to check without actually using the cameras so if anyone reading this can offer any advice please feel free to comment.

So far the best web site I have come accross for advice is http://www.imaging-resource.com/ but there is simply too much information to take in. I guess one thing I do need to know is if it is better to go for a higher zoom and accept lower megapixels or are the megapixels more important when taking shots of wildlife that might be some distance off.

I guess the bottom line is that no matter which of these cameras I choose, they are all cheaper than the Sony I bought 4 years ago and I dind't think so hard about it then.