Hi Paradise_Gourami
A 29 gallon tank is a nice size.
You will really enjoy it!
And planning it is great fun, too!
You mention, in your signature, a "dwarf catfish." What is this? If it's a cory of any kind, you should really add a few more. You will see the difference in his behavior. Because they school, they need companions of their own kind. I'd add 2 or 3 more and perhaps get 3 of another type of cory, too. Kuhlii loaches are a good choice, as well. Get at least 3. These fish would give you an interesting bottom.
For the top, I'd stay away from the blue or opaline gouramis. A pair of pearls or moonlight gouramis would give you more agreeable fish and both of them are lovely.
The center level could house a school of glowlight, neon or cardinal tetras. Or any of the many beautiful tetras that are available. Barbs could get nippy and I would avoid them.
A few guppies would add activity and color. Platties would do the same.