ataxian
PALE BLUE DOT
The D020 is my favorite little bubbler with a ash catcher it has volume enough!Think part of your issue might be with terminology. By s shape j hook do you mean a sherlock type or something else? I think some of the Chinese vendors call them "s shape", but don't think its common term here. FWIW a picture - or link to one - is worth a thousand words, if not more.
Check on @ataxian 's posts in this thread and others for looks at plenty of glass with j hooks and ashcatchers (and many other pieces). Don't recall if any specifically show a nano on them, but he has all kinds of mad scientist glass combos where you can see many things if you look.
In my personal advice, I'd get a j hook for use dry if you like and a cheap bubbler for wet. Putting j hook and ashcatcher together then putting nano on it can certainly be done, but could be a bit tricky and take some practice to use easily. There are many bubblers out there from China. D020 still remains a favorite and is relatively cheap here, though not sure about shipping costs to UK. That same vendor (sunshinestore), has many different pieces and a pretty good rep here on FC. More diffusion can be pretty, but less will preserve more flavor. Honeycombs and trees (arms) generally create more diffusion while showerhead types with slits are easier to control diffusion and keep it pretty low.
You may want to reconsider if the j hooks you're looking at are like these on sunshinestore here. The flat mouthpieces have a smaller hole (and probably with varying sizes due to Chinese QC), that don't allow as much airflow and are usually more difficult to clean.
Just listen to @Ratchett above. He just beat me posting but about how much GMTA!
D022 is another good one.
JHOOKS (sherlocks) DRY or wet with a ash collector are pretty functional!