Fishdawg,
Generally, it is not a good idea to put cichlids in a planted tank (real plants, of course) since most dig in the substrate when breeding or otherwise munch on plants. If your plants are fake, then no worries there.
My experience has been that bottom dwellers, other than pleco's, are quick to get picked on by cichlids and my CAE even got schooled by some cichlid fry once and so I moved him. I might be worried about the corys a bit, but of course it depends on what cichlids you are going to get. Most smaller cichids do spend quite a bit of their time near the bottom of the tank, so your corys would most likely be noticed. Still, I have kept clown loaches and even some aggressive cichlids together with little problems.
The angel is a cichlid, technically, however they would be very open to nipping by some smaller, faster cichlids and so I might reconsider keeping them all together. The best thing to do, when keeping fish other than a cichlid or certain cichlids (like angels) is to keep the least aggressive fish as being very fast and very active so that they can escape quickly. I keep a school of 8 tiger barbs with my cichlids and everything is nice and quiet, usually.
There are some good cichlids to get for your situation though. I think Rams would be a good choice (depending on their Ph and water type requirements which I am not completely sure of). You could google to see more info on them and also try searching for "butterfly cichlids" which I believe is the other name used for Rams.
So, in short, you would be looking for some very non-aggressive cichlids that stay relatively small due to your tank size. The good thing is though, if you find a good fish to stock with, many times it is benificial to overstock with cichlids and simply do larger or more frequent water changes as well as maybe increasing your filtration system.