They would be fine. I would make the angel the last to be stocked. Guppies get along with almost any other community fish

Keep in mind that Angelfish get quite large. Large enough to eventually pester &/or consume not only your Neons, but also any guppy fry produced.

The angels may eat the guppies and the neons. If you want to try the angels make sure there's lots of hiding places for the smaller fish.

corydoras are schooling catfishes and need 3 + of them to be happy. watch out for tiger barbs and other fin nipping fishes that are otherwise recommanded for community tanks.

I have a few panda cories with my guppies and they get along great.

Essentially all the snmall tetras - neons, cardinals, glowlites, silvertips, etc.; leopard danios and zebra danios - pearl danios are also OK but a bit large. White Cloud Mountain Fish are ideal. As Yanggers said, tiger barbs are aggresive but cherry barbs and checkerboard barbs are fine. Platies should be fine but swordtails are too large and can be aggressive, in my experience. No cichlids, including angels. All corydoras cats are great, and I agree - get at least three of a kind - that large a tank would support 6 in all likelihood. Mollies are also OK, but are hard to keep healthy. A native livebearer, Heterandria formosa, is even smaller than guppies but should be able to live with them.