Set a budget then go to a shop with lots of pianos. Say between £1000 and £1500. Then get the salesperson to set up demos for all pianos within that range, price blind. Trust your ears and your instincts and go for the one you like best, irrespective of price.

The differences will be in various component parts of the keyboard. EG the type of keys (construction, response, weight), how the piano sound is generated (size of samples etc), the onboard speakers (I'm assuming you want one with built-in speakers.

Yamaha are good at home pianos. For stage work I like Roland and Nord but that's not really what you after I don't think.

Set a budget then go to a shop with lots of pianos. Say between £1000 and £1500. Then get the salesperson to set up demos for all pianos within that range, price blind. Trust your ears and your instincts and go for the one you like best, irrespective of price.

The differences will be in various component parts of the keyboard. EG the type of keys (construction, response, weight), how the piano sound is generated (size of samples etc), the onboard speakers (I'm assuming you want one with built-in speakers.

Yamaha are good at home pianos. For stage work I like Roland and Nord but that's not really what you after I don't think.

...but I did research it all about 3 or 4 years ago as my son wanted a piano. He was a decent keyboard player back then but wanted the real thing.

His keyboard teacher said he was to old to start learning piano as he'd just get fed up of the monotonous practise(he was 13 at the time)so we were worried about the amount to spend. Happy to say he's stuck with it and he's at Grade 5. It's a Yamaha Arius YDP140 he has and he says he can hardly tell the difference between it and the *real* pianos at school.

I have it in my head that we paid around £800 and Amazon confirms this, though we didn't get it from Amazon.

You usually need to buy a piano stool seperately.

http://www.amazon.co.uk/Yamaha-YDP140C-Digital-Cherry-Finish/dp/B001BWUR...

but I have a Yamaha electric piano. Cost about £600, ten or so years ago - a very nice and reliable instrument. Would echo Jorrox's advice about visiting a specialist shop, trying some out, and listening to advice.
Clavinovas? They are very sophisticated things - if you want whistles, bells, backing tracks, etc. they are the thing; but for simply playing the piano, I'd say it was overkill.

Enjoy your instrument, whatever you choose.

It's wonderful having a piano. I love my baby grand, it's probably my favourite possession.

As suggested above, go and let your missus try out all the pianos. There will be some that feel more right to her than others. Make sure it's got a headphone socket (not all of them did when I bought my Clavinova, surprisingly).

I used to own a Clavinova, that was splendid (although as Adman says above, there's the overkill thing, but I enjoyed it). The weighting was beautiful and it was truly a pleasure to play. Tis the only digital piano I can give you any feedback on tho, so I'm pretty biased.

Wonderful idea for a present, enjoy.

Some really helpful comments, thank you very much. Initial research by Mrs eddie suggests that one of the Yamaha Arias ticks the relevant boxes, possibly the YDP161 which seems a bit louder and has a slightly better hammer action than the 141. Not many bells and whistles but that's not what she's after. We'll go out and audition a few to see how they measure up. Quite looking forward to it.