Hi,
Keyboard touch is a pretty tricky preference to pin down; when one is aware of what's available as you evidently are, it's very hard to find that one perfect answer (and stick with it). That said, there's no reason why you can't take a practical approach.
The Cherry is the only 'board springs (ha, pun not intended) to my mind that you can buy in the UK with the layout and clicky keys, but yes, remapping is always a possibility if you're fine with the actual keys and the legends.
In addition to the suggestion of the revised "Mighty Mouse", are you aware of the
Unicomp Endurapro [click the picture for a big one]? It's a reduced size design over the 101/2 "Model M" and has the Windows keys, and Trackpoint. It does come in black, though IIRC Unicomp don't want to manufacture black keycaps (or is it just black keycaps with legends?...) due to cost, so you get metallic grey in such case. Alternatively they also do the more traditional case in UK layout with or without Windows keys.
I understand Die Tastatur II is essentially a rebranded G80-3000, and the earlier version was the rubber dome Keytronic Model M lookalike.
Age isn't necessarily an issue; IBM bucklers tend to be made of lasting materials and so if not abused remain good cosmetically and practically for some time. Other manufacturers vary; strictly cosmetically Cherrys generally age reasonably, Dell AT10x keycaps fade before the case does; many clone 'boards fade badly. Obviously, black is ideal in this case...
With regard to switch age, on my AT102W which evidently had heavy use [shiny keys, another thing to watch out for], the ALPS are generally consistent but a few keys do feel different; on my more lightly-used ALPS 'boards there is no distinction. You definitely don't have to hit the keys any harder though, if anything those that are worn are softer. Again, IBM 'boards tend to age well and individual assemblies are easier to source than most ALPS switches. Cherry switches I don't have enough examples of to be certain. The action in good rubber dome 'boards can last very well, quite possibly better than some keyswitches.
All keyswitches will make some additional noise over rubber dome 'boards, though far from all are designed to click. The quietest are probably low-profile scissor switch types, while I recall lore of exceptionally loud switches from Scarry-Garcia the loudest I could relate to is a 122 key Model F (at least, if you get same resonance you do as with a 122 key Model M in that same housing), plus you could add an electronic click... Now to persuade the kbdbabel guy to make these a priority...
Definitely beginning to ramble, so I'll leave it there for now.