I also have a 29 with 2 angels in it that are probably about 6 inches tall. but i bought them as small and have gone through 6 fish. I had 3 big fish, but one of them died a couple months ago. I think that one of the other angels killed it. Personally i don't think that it will matter what size fish you get because angels do grow relatively fast. The only advice I would give is, as you may already know, buy all of the angels at the same size because they are semi-aggressive and will pick on smaller fish of the same species until dead. Good luck on whatever choice you do go with.