Can anyone advise me on the best purchase among this lot.

Yamaha CP33
Roland RD300
Yamaha P140
Korg SP200

I am looking for a keyboard that will take a lot of playing - I'm sore on the keys! I want a wide choice of piano sounds.

I chose the CP33 over the RD300 because I liked the touch and the sound better, but the Roland has more features and more sounds. Don't know about the other two.

Does the Yamaha CP33 have built-in speaker system for home use? Thanks, Mahlzeit.

No, you will need to buy separate speakers (or just use the headphones).

The P-140 has built in speakers, and if you buy the "official" Yamaha legs for it, it turns it into a decent looking furniture piece. I prefer the Yam action to the Rolands, but this is entirely a personal thing. Some people love Roland action, some people like Yamaha, you just have to try it out for yourself! They are both awesome brands and great pianos.

I have noticed that the C3PO is a bit larger and more fancy looking than the R2-D2, but the R2-D2 is more compact and portable and even has wheels. The C3PO has some rather long, fragile looking metal legs. The R2-D2 also has a very cool video recorder/playback feature! Also, the R2-D2 has a greater variety of sounds but they all sound more synthesized whereas the C3PO has more natural sounds some very closely resembling the human voice...including a VERY realistic Roddy McDowall emulation!

just kidding! :p

Heh heh. I wouldn't want a piano that sounded like R2-D2.