Yamaha seem to be making better and better pianos using ever cheaper materials and construction techniques. Until recently I have never liked Yamahas, as these and other cheap imports can have a shallow, hollow feel to them. However, the new Yamahas play really nicely, and don't feel like they need playing in. Not sure how well they will last, or if I would want to keep one very long term (25 years+). I would certainly consider renting one, it gets tuned, delivered, you get the very best years of its life if you pay a bit more and rent one from new...
For me, the touch and responsiveness of the keyboard is normally at least as important as the sound. This is where uprights usually loose, out, touch, over a baby grand which you don't have space for. But a massive 100year old German or American upright, bought privately for around $1000, that covers most of the wall, can make up for so much else, and you can totally get lost with the instrument, becoming one, sucked in by the richness, range and immense power. Many on here will recognise that feeling. I expect few will say they have felt this total enveloping feeing like that with a Japanese or Chinese upright. You can get this effect with their grands though.
My advice is to avoid the ones you have seen already and stick with digital. Learn to play something yourself on digital, slow with nice chords, perhaps a trilly bit in the right hand, and for the next couple of years look for an American or German piano that will cover most of your wall, that you yourself enjoy. This is what you are asking for, a tall piano with great sound. Japan or China are historically weak in this area, but instead good at making small, compact, reliable. Give your find a year to settle in to your house, regular tunings, and keep the kids playing on both. Hook the digital upto Midi and a PC, let your kids experiment with fancy sounds too. Don't worry though, the kids will soon realise the big piano can somehow do so much more sound wise than the PC!