It looks to be a low light tank, so a moss carpet.
Its a 60w, 40h and 35d in cm. The light is a 60cm dual bulb T5HO fixture, so i assume its in the medium to high light. The pictures are a bit modified... I'm really hoping its going to be good enough for HC, but time will tell!!
If it is nano, then use chili rasboras. I think the red looks good against a black background. If it is a bigger tank then you could use harlequins. I do prefer chilies.
I'm really inclined to go with the rasboras... Keep hearing how good and tight they school, and how active they are. Hope they have some in my LFS, which I'm planning to visit as soon as my tank is planted... (The plants should arrive tomorrow.) Never bought any fish online and to be honest I'm a bit worried about doing it... Any words?? Favour or against??