I am searching for realistic sound. My top priority sounds are:
*Piano
*Strings instrument
*Wind instrument
*brass instrument
Since strings, winds, and brass play perfectly well from a hammer action keyboard but pianos don't play as well from non-hammer boards, I would try to get something with a hammer action. If budget prompts you to stick with a non-hammer action, at least try to choose one that is among the more playable non-hammer actions for piano.
When comparing boards, sometimes, boards that are more expensive in some countries are less expensive in others, so I don't know for sure what may or may not be available in your price range, so I'm going to expand from your $1400 to look anywhere up to $2000 U.S., in case any of those models are closer to your price range where you are.
In hammer action boards with strong piano and orchestral sounds, one of my top choices would be Kurzweil PC4. If that's out of budget, then look at their SP6 which will give you most of the same sounds, with the big limitations being that you lose the expressivity of aftertouch on your orchestral instruments and the expansion memory for adding additional 3rd party sounds (or sounds you could sample from your VSTs, though getting good results doing that is not always easy).
My other top choice would be Yamaha MODX8 where, for the sounds you're asking about, the main tradeoff vs. the PC4 would probably be the loss of aftertouch. I can't tell you which sounds better, that's subjective, but both are quality boards when it comes to piano and orchestral sounds. At lower cost, the MODX comes in non-hammer versions (MODX7, MODX6), but they really are not good feeling boards for piano playing (and also, 61 is a pretty restrictive size for playing piano).
Behind those, I would place the Roland FA-08. My opinion (though yours may differ) is that Roland pianos sound less natural than Yamaha or Kurzweil, and unlike the MODX8 or PC4, you can't load your own sampled instruments into it (nor does it have the aftertouch of the PC4), those are the reasons I move it down to the second tier behind those boards, but it's still good. The strings, wind, and brass are not so impressive out of the box, but you can load two downloadable expansions into it. and there are better orchestral sounds on some of those. The FA is another where non-hammer 76 and 61 key versions are also available at lower price, with less satisfactory piano playability. Roland also offers the less expensive Juno DS88 (and 76 and 61). I think its piano is another step down (though that can be subjective) and you can only load one of the expansions instead of two, which will limit the selection of higher quality orchestral sounds available to you at any one time, though it does add a small amount of memory into which you can load your own sampled instruments, which may make up for that.
Lastly, I'd put the Korg Krome, followed by the Korg Kross. I haven't played the Krome personally, but in general, I have not found the orchestral instruments in most Korg workstations to be among my favorites (though I never played with EQ on them as Biggles suggested). Biggles mentioned the Korg arrangers (like the PA700/PA1000), which I think actually sound quite good on orchestral instruments, but they limit you to 61 keys which, as I said, is limiting for piano, which is one of your main needs.
Here's an alternate approach... a pair of boards. You could start with one of the cheaper-than-88 61s focussing on the orchestral instruments (Korg PA700, MODX6, FA06, DS61/XPS30), with the idea of adding a 7x or 88 for better piano playability in the future. Choose a second board with a standard 5-pin DIN MIDI Out jack, and you will even be able to use it to play the sounds in your 61, if you'd like. That could be especially nice if you choose a piano board that also gives you aftertouch, though in the lower price range, that will limit you to either soundless controllers (like the Studiologic SL73) and/or non-hammer actions (like the Numa Compact 2/2x... though as non-hammer actions go, that is one of the better piano actions).
