I just joined a band recently. I currently have a Roland digital piano and am very happy with the quality, but it is not by any means the greatest live performance unit. It is kinda bulky and doesnt have a lot of features i would like. Does anyone have any advice as to a keyboard I should get for this purpose. Here is what i am looking for and any advice would be appreciated.

1. Good sampled instruments such as varoius strings and a good piano sound as well as a wide variety of synth sounds and maybe FX.
2. Something good for a live show in a rock band, portable, versatile, ect...
3. under $1000.. the less i can get away with the better Hopefully around $500.
4. I like roland, but am willing to buy other brands that migth be better in this area.
5. I dont need anything real fancy, this is just for starters.

Also if anyone knows a good place to buy it or maybe even a used one let me know..

Thanks