Very nice tank! I don't know that I'd replace the neons, not all angels eat them if the angels were smaller when both were new...but it may.
I love both brilliant (rasbora borapetensis or sometimes called red tailed) & harlequin rasboras. Black neons are subtlely pretty & very hardy.
I love bottom feeders & would get more corys. I like WYite's idea of a mix of albino & normal colored...but there are some "other" albino corys these days, sterbai (the pectoral spines are orange) & paleatus, not as "usual", I don't know how to tell them from aeneus. All corys get along, but a chance breeding & maybe a survivor is fun too. They can tell species even if we can't...