Lowe Alpine’s Altus packs are brilliant – carry really well, lots of stowage options – stash pockets side and front, two lid-pockets, main compartment with zip-option sleeping bag bit and panel access – at least with the 42-ish litre one – to the main compartment. Oh, and decent belt pockets too. It’s enough for me, but I guess how you store and organise things is pretty personal.
The problem with big, retro-style side-pockets is that technology has left them behind. Karrimor does a Jura 35 with side pockets, base pocket, lid pocket etc, but I suspect it’ll carry like a bag of bricks and is a bit small anyway.
Proper alpine packs tend to have a lid-pocket and a main compartment and maybe some compression straps / cord / daisy chain loops. I think it’s more that the sort of stash pocket lay-out that started with adventure race-type lightweight packs have gone mainstream.
Anyway, at around 40 litres, I’d get an Altus. Try a few packs on with a load and see how they feel would be my start point. I don’t think there is a good quality modern pack with trad side pockets etc out there though.