Depends what you want to hatch.
White rooster would only give you white offspring.
Back will give black and/or blue.
Blue will give you blue, black and splash.
Splash will give you blue and/or splash.
Any of the blue, black or splash that had a white parent would give you the same as above plus some whites.
I wouldn't mix any of the other colors like buff, red, partridge etc. That's just me though.
A blue rooster that carries white would give you the most variety.
Props for looking into replacing that rooster. Its always sad to hear when people keep mean roosters. Especially when there's kids involved.