The RM2 is the modern version of what you have now.
Hi Fred, and welcome to the VMPS Circle.
I think B, suggests a good solution, and the RM2, is a speaker that can "blend" with the Tower II's very well.
Another used pair of Tower II's might be hard to find, since those who have them tend to keep them.
The RM2 is of a similiar size, and performance.
You could use the RM2's for the fronts, and the T2's for the second pair.