I would keep a close eye on the angelfish, over time. If this happens to be a male, it may take a dislike to the gourami, especially the male, as males are highly territorial for both cichlids and gourami.
On the corys, I know there are aquarists who do not like to mix species in the same tank. The only fish-related reason for this is that some may/will cross-breed, and as responsible aquarists we must be careful not to introduce hybrids into the hobby should we sell or give away such offspring. I won't go into all the reasoning behind this, just mention the issue. I have always (over 20 years now) maintained mixed species of corys in my larger tanks. I have near 40 now in my 115g, with some 12 species represented. Some have spawned, and I even have fry that survived predation in this tank. I do see cross-species behaviours that are the preliminaries to spawning, so I've no doubt this might occur with some species. But within the confines of your own tank, and retaining the fry yourself, I don't see an issue if this should occur.
On a side-note, the 150+ recognized species [Fishbase currently lists 159] presently classified in the genus
Corydoras are almost certainly not a monophyletic grouping, so the genus is polyphyletic. This means that some of the species did not descend from the same last ancestor. In other words, there are several species within the genus that are not that closely related genetically. In 2003, the ichthyologist M.R. Britto proposed a reclassification of the entire family Callichthyidae (represented currently by the genera
Aspidoras, Corydoras, Brochis and
Scleromystax) into nine clades or genera. Subsequent studies on species within these genera have generally accepted this thinking, but considerable phylogenetic study will be needed to finalize it. The 2011 work by Alexandrou & Taylor followed Britto's concept and includes all species including the "C" numbers. You can read their study free online; the re-classification is quite interesting and we will have considerable name changes when this is sorted out:
http
/www.academia.edu/5890874/Evolution_ecology_and_taxonomy_of_the_Corydoradinae_revisited
Some work has confirmed a few changes. The genus Brochis is now defunct, the three species having been moved into Corydoras for the present. I say for the present because the authors themselves admit that Brochis will eventually turn out to be a monophyletic genus in its own right, though with some different species. Thus, the three Brochis species are temporarily moved as they share traits with certain other Corydoras species that will no doubt all be together eventually. Another change already affected is the transfer of four species out of Corydoras into Scleromystax, namely S. barbatus, S. macropterus, S. prionotos, and S. lacerdai.
Byron.
