To get these two to co-exist peacefully in a 125 gallon system you will need two things: first, lots of rock so that each can have a territory and a place to hide; and second, a tremendous amount of luck. Sometimes two fish will just kill one another, and yet an other pair of the same kind will become good friends. It depends on the personalities of the two fish, so you pays your money and takes your chances. But do have a plan "B" to activate should the two not get along.