I'm not the best at stocking advice, but this sounds like it will be a lovely tank to me!!! I'm a huge fan of Pearls, and the Rummies should be large enough not to be in any danger from them. I don't think you can go wrong with Cories, either. Are you thinking of Salt and Pepper Cories? I'm beyond in love with those little guys. . . the shrimp *might* get picked on by the Pearl, and Amano can't breed in fresh water, so that may be worth looking father into. The females of this type get fairly large, so they might be safe.
I'm interested in seeing what other more experienced members have to say - and to watching this tank develop! Be sure to keep us posted - and good luck!