Corys: all species are fine with angelfish. If you go with different species, 5-6 of each is quite nice. You are correct, with corys the more the better, but your space is not limitless.
In a 55g tank I think a total group of up to 20 corys would be nice. Especially with lots of bogwood chunks on the substrate. They love having wood and plants to browse over continually.
For tetra, groups of 2 or 3 species would be fine, with 7-11 of each depending upon species and your preferences. With either rummynose species, more is always better, never less than 12. They are very tight shoaling fish. And the False Rummy, Petitella georgiae, is better with angels though not as brilliantly coloured as Hemigrammus bleheri. I have both together in my 115g, 20 in all. Spectacular. If the angels are smallish the Brilliant Rummynose should be OK. The False is less easy to find, unless you have a store that imports from South America.
Most of the species in the Rosy clade of Hyphessobrycon are ideal with angelfish. There are some 30 species, several are in our profiles (use the scientific name listing and check the species in Hyphessobrycon. Hyphessobrycon bentosi is my favourite, the colour is astounding. These species are disk-shaped with complements angels nicely. Some can be nippy, the Bleeding Heart for instance was nasty for another member. The phantoms (black and red) are in this group too. Avoid the Serpae, they are notorious fin nippers and angelfish are too much of a temptation.
Someone mentioned Black Widow Tetra (Black Skirt is another common name), these are risky; while this group or that group may be OK, the species as a whole does tend to be nippy with slow fish and is best avoided. Same for Emperor Tetra. I had to get rid of mine because the males terrorized all the other fish in the 115g tank. Here again, different fish can have varying temperaments. But to avoid "possible" trouble, take the advice in the profiles and avoid the species that have these traits.