Having spent the last 7 hours doing a LOT of research and I've come to a few decisions.
Will be buying second hand. Something around the 2018-2019 vintage seems about right to get what I want in terms of having the newer 1x gear sets and I definitely like what newer frame geometry has to offer.
Definitely want dual suspension. I wanted it so much last time that if I buy a hard tail now ill be wanting to upgrade it in a month anyway. My son is buying a hardtail and we'll have the same size bikes so it wont be hard to use his if I'm in the mood for that. I'll also borrow his bike to go to-from work and when I just do casual path rides with my wife.
Dropper post absolutely required. Either included or upgraded to soon after. Backup being fashioning a 'slider' post out of my wifes gigantic black dildo.
Shimano deore gears at a minimum, GX if SRAM. From all of my reading SRAM SX is dearer than deore, but lags behind it.
Fork... not a massive deal as I'm happy to upgrade it at a later point should I not be totally happy with what comes with it, buuuuuut I'll be hoping for something better than a set of 2007 RST Gilas
... I did notice that sr suntour air forks are a bit nicer than others of the brand used to be back in the day, but still a bit... sticky? compared to better dearer forks.
Only thing left is wheel size... I guess, based on what I've read, I'd prefer 29" but if I see something that meets all other requirements and it has 27.5 then so be it.