Breeding pair of Angelfish could work. Problem is that they are very difficult to sex (male/female), and you would need to get a group of five or six and wait to see if a pair forms. I beleve it would be six months before you would see young angelfish try their hand at spawning. At this size, and with the number of Bristlenose you have,the tank in my view,,would be difficult to maintain water quality in ,and once Angelfish form a pair,,they are often intolerant of other Angelfish or at least that's been my observation.Then you would need somewhere or someone to take the remaining Angelfish so that the breeding pair did not injure them.
Bristlenose (one) might ,or might not be be ok ,but with the numbers you have presently,they may find the eggs of Angelfish a nice snack should a pair lay eggs .
If you are set on spawning,or breeding fish,.then more tanks should be considered to house breeding fish ,and or growout tanks for fry (babies). Opinions vary.,this is mine.