40B is a nice size, especially starting with a blank slate like that. What appeals to you?
I personally love those dwarf neon praecox rainbows. But there are a lot of really good options. If it were me, I'd look into one fish that I really wanted, and then go from there compatibility-wise.
Also, if you like catfish, check out hoplo catfish (see my avatar). They are basically hotdog size cories, non-aggressive towards any fish and social with each other. For some reason they aren't that common, but they are super easy / hardy and have good personalities. Just can't have them with particularly aggressive fin nippers - I had one named "Stumpy" for this reason...
The males are so protective of their young (and it seemed to carry over to any small fish). They even protected rasbora fry in the same tank! Only thing is that you need another tank (or divider) once eggs are laid. They will drive the female(s) off with a vengeance once they have a nest to guard.
Amazing to me is I started this one with only 1 bronze crypt. They have taken over! Anubias are showing nitrogen deficiency, so I guess I go shopping this weekend for something to put in it until I decide on what I want to do with it. Got to trim the yellowing leaves. Or maybe leave them for the snails. Hrmm.. lol
I usually like to get fish that are not normally found in the 'big chain' stores. Not much else in my city. Most of the time I end up ordering fish shipped to me.
There are 3 pieces of wood in there, but hard to see it with the jungle. Its manzanita wood. I like it because its smaller but has a lot of 'character.'