Welcome Keith.
Firstly, have you played a 1000?
There are quite a few menu and functional differences but I would expect the sounds to be similar.
There is a new OS update out which may change a few things from what you see online.
I see you are in Cider country and hence lucky in that we in the UK do seem to have the best Korg team there is. KorgUK have their own website for Pa owners which is Korg World and if you go onto their website you will see links to the webinars that they produce, there have been about 20 so far and they are live and interactive but available to watch after the event.
These are a mass of very useful information and whilst the presenters do use a 4X the functions are very similar on a 1000 and a 700.
Additionally online there is Korg’s Video Manual series available that go into detail in each of the features of the Pa which you may find very helpful in your choice.
Personally I would save more cash and buy a Pa4X, I have just sold my Pa700 but would not consider a Pa1000 as the differences between that and the 700 is not enough for me (different keybed, more memory, more sounds and vocal processing) to spend £500 more than the cost of a new 700 and go for a 1000.
Finally I do not know how you operate your 800 but the new systems in place with the Pa series leans heavily in using the Songbook and Setlist function, here a Style is saved to be a Songbook entry and it is then customised to suit the song and saved, the original Style remains unchanged. Load the Song and play it is as simple as that. It is also very easy to save and customise Keyboard sets and individual sounds. Plus Korg have over 40 Bonusware Style packs available foc plus many additional soundfonts.
Good luck.