Well, everyone hears things differently. Yamaha I think makes one of the best digital pianos. Have you looked at the DGX 650? Not a bad keyboard for the money. It weighs in at around 47 lbs. Keep in mind if it has internal speakers, the better it sounds, the heavier it will be do to the quality of the speakers. The dgx 650 sells for around 799.00... Hear is a link you can listen to.

http://www.kraftmusic.com/digital-pianos-and-keyboards/digital-pianos/yamaha/dgx650/

On the high end of the spectrum is the Nord 88 key digital piano for around 4000.00. To me this is the best sounding piano out there. No on board speakers. If you can find one is the CP300 or 250. They are a bit older but sound beautiful... Heavy tho at around 70 lbs.

The Kraft music website has good videos for most of all what they sell and you can take a listen. I currently use a Yamaha MOXF 8. It is not a dedicated piano but has some great pianos in it. Only weighs about 25 lbs but no sspeakers.
Whatever you decide... It is not an easy choice... Good Luck....Ron