Okey, if that's the case, I suppose good piano sound and feel is a must.
First of all, as you will probably want weighted keys, since you're used to playing the piano, you should definitely get a full-size 88 key keyboard.
The cheapest price I've found on the Korg M50-88 is €1729, which exceeds your budget. But to me it sounds more like the Yamaha Motif series should be of your interest, as Yamaha is THE best when it comes to piano sounds.
However, I just did some quick research and found that all the 88-key Motifs are above your budget, but my mind crossed the
Yamaha MM8, which might be of interest. (found a demo
here which demonstrates it's piano sounds)
If piano sounds will be the most important, you should probably definitely go with Yamaha, but if you think that you will be using a lot of other sounds too (like leads, pads, drums, brass and such), you might want to do some additional researching.
Unfortunately, I don't really know that much about either Yamaha or Roland, except for what I've just said, since I'm too obsessed about the M50 xD
Regarding the accessories, you will at least need a sustain (damper) pedal, and a keyboard stand. Then there are a few extra optional things (like a footswitch to change sounds by pressing a pedal, or an expression pedal to control some effects), which depends a bit on what you intend on playing.
Hope it helped a little bit

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