I need help finding the right keyboard.

Hi everybody. I´m Fisklingur and I´m new here! Nice to meet you all!
I need some guidance.
I can play a few instruments but my main instrument is the piano.
I’ve been thinking about buying a keyboard and I need some advice on what to buy.
I want to use it for composing and recording to cds and have fun playing it. I’d prefer it to be touch sensitive and good sound.
I’m totally new to this and it is so much on the market that I feel completely lost.
I’ve been looking at Yamaha DGX 505 adb, Tyros and Tyros 2(What’s the difference?), and Casio PX400, but I haven’t tried any of those I just read about them on the internet.
If someone can advise me on a good keyboard that is easy to work with and has all the latest features and possibilities I would be thankful.
Thanks in advance
Fisklingur

If you have questions about Arranger Keyboards (keyboards with programmable acomponiment/styles) may I suggest that you post them over at the General Arranger section here. That's where you wil find a lot of Arranger KB users. They are a great bunch and you'll get all the answers and help you need.

Thank you I´ll do that