Marcel,
If money will be tight, I would suggest a few things for you to consider. The Korg SP200 sells right around $800.00 in the US and has 88 weighted graded hammer action keys and over 40 sounds. The Yamaha PA80 is about $100.00 more ($899.00) and add a few more features. Both of these need powered speakers but that can be a home stereo or computer type powered speakers which can run as little as a few dollars.
At the next level would be as Squeak mentioned the Yamaha YDP121, but this has been discontinued and a new model the YDP113 will be replacing it at around $1000.00. The difference between the YDP series and the others I've mentioned is the YDP look more like a real piano with less voices and features than the SP or P series I've mentioned first.
If you would like a great feeling piano with arranger features take a look at the Korg SP500 for around $1500.00. It has everything an arranger keyboardist wants except for a floppy disk drive. This is a lightweight alternative and a "best of both worlds" keyboard. Piano/Arranger and inexpensive.
There are some $500.00 options as well from Yamaha with 88 keys, but these are not hammer weighted type and feel more like a "keyboard synth" action. Yamaha YPP200 is one model and coming out later this year is the DGX500 for about $795.00 that will be an arranger/88key Light Action/disk drive, built in speaker model.
Roland also makes some nice digital pianos, but they start above $1000.00 for 88 weighted keys. A new model from them just shown at the Summer NAMM show for under $700.00 only has 76 keys and light action (model is EP760). Two new pianos with graded hammer actions have been introduced by between $1200 -$1800.00
This is a start at what I would be looking at.
George Kaye
Kaye's Music Scene
Reseda, California