I agree you are overstocked. Your angels should be fully grown in 2 years - about 6" long and 10" high. As they mature there is a high probability that one of the angels will kill the other. That's just genetic and the fact that they "grew up together" won't make any difference. My bristlenose is 8". They are messy fish (biologically) so no more than 1 in a 29G.
You don't say what type of beta, but if they are beta splendens you should be aware that these are naturally solitary fish, so that may not work out.
FWIW never believe the advice given by someone trying to sell you fish in a fish shop. Seriouslyfish.com is a reliable site for researching fish requirements and compatability.