How many Hens do you have? If you have about 20 or more, 2 roos will fight for which hens they want and then claim different areas. I have had multiple cocks together without an issue. I'm careful to introduce them according to a strict protocol. (quarantine then gentle introduction then introduction in a wide open space).
RIR's can be agressive but the RIR rooster's I've had were really nice.
Silver Grey Dorkings are a great choice, very beautiful and their hens are as well.
Buckeyes are also very nice rooster's, if you partial to a dark bay-near black red rooster.
ISA brown rooster's are docile as well, and so are their hens.
If you prefer a dark colored rooster, Langshans and NJ Giants are also very good choices.
Breeds to avoid because of the other rooster:
Game birds (prone to fighting, noisy)
Bantams that are very small (serama's, Japanses, etc.)
Phenoix
Samatra
Crosses of the above
While the above birds can be sweet as sugar, you can also get one that has a lot of chicken aggression but is the cuddliets darn thing to people. Since you're wanting eggs, you want something that will pass on some productive genes and sizeable eggs. The bantams are cute, but smaller eggs.