I'd start from what do you want out of the bike. Is it to ride and get a bit gnarly, a nostalgia trip, something a little on the fancy side?
Sounds like you liked the Kona and zaskar you owned, so they would be a decent choice for a trip down memory lane, a familiar path well trodden.
Nowt wrong with that, I've done similar with bike choices and why I own and won't sell my GT Team RTS. Had a 2 bitd, it cracked. Wanted to find another, but luck was on my side and I found a nos team frame in my size. It was in the states but needs must so bought it.
I then went on a trip of discovery with other builds. Bikes I wanted but couldn't afford as a kid. Owned many, some were great (a giant CFM carbon lugged frame, I regret parting with that, I dynatech torus, full ti, still have that gathering dust as don't get to ride much), some disappointed (a Klein rascal in gator fade, looked so good but I got numb feet and hands even on short rides).
Material didn't seem to matter, all were sound, as some have said, it's about the life they've led.
If I were looking for a build now, I'd probably look for a steel Saracen killi with the lovely wishbone stays, got one, but needs a repair. Or a ti frame, as they are lovely to ride.
Nowt wrong with alloy either.
I would love to do a resto mod estay.
Parts can be replaced or sourced so I'd not worry about that. Forks are an interesting part. Suspension wise, I've tried many, older forks are of their time and you can still find a good set and look after them. Pace are a good bet as user just backdated on here is an ex pace employee and has a business looking after old forks, so you can get them as good as new. Older Judy's are supported by srp parts wise. Marz seem to just be bomb proof so a good bet. I've gone down the road of getting as new a fork as I can and sourced lowers with v mounts, such as 32mm sids and rebas, fox floats in 32mm. Modern damping and tech that supports our old braking choices (or limitations).
Good luck in your search, I hope you find the frame you want and turn out a bike you enjoy riding.