Okay, yeah I think getting some sort of hiding place for him will be beneficial. Have you tried turning off the bubble stone at all? I know it's on super low but it's worth a try to see if it's that bothering him more or not.
And yeah, taller silk plants would be good, live is great but that's entirely up to you. And I say no on the catfish, they mean Corydoras and they are shoaling fish which means they have to be in groups for social reasons otherwise they can be extremely skittish and shy and potentially die. Now there are cases where a catfish has been happy to live alone but I wouldn't take that chance :-/
If you want to get some cheap good silk plants online, drsfosterandsmith.com has some really great ones for a dollar something each! I've actually just ordered quite a few for like QT tanks so they're not just sitting there doing nothing when they're sick so that's good. I'll tell you about their quality when they come in which should be today or tomorrow/friday
but they look good online! lol
And yeah, nerites you usually have to go to a local store that's family run or something because the bigger stores won't ever have them. You can also order from online as well; AquaBid/Ebay are good.