Hi everyone

I used to be a keen photographer when I was younger and am looking to take it up again. I am particularly interested in portrait photography. I was wondering whether you think it better to buy a recently released camera with a high megapixel sensor such as the Sony A300, or buy a more professional camera, such as a Nikon D2H, which is used?
I appreciate the fact that a lot has to do with what size I plan to print images out at - I estimate you could probably get a good quality print from 4 megapixels at A4/250ppi? That's seems plenty big enough. Do you think I really need 10 megapixels?
Again, I understand it gives you room to 'play' ie crop the image and so forth. But if I am mainly portraiting people this is not so important.
Will I find a camera like the D2H has more features or a higher quality image than the Sony, or has technology moved on so much that the D2H is now not worth buying at all?

Any comments would be most appreciated.

Thanks!
regards,
Robsa