If you want to go full bore.
The JV Digital Engineering products are great.
My XTB-IIR 2 Phase Repeater blasts X10 signals all over the house.
I have seen good reports of the plug in XTBR.
http://jvde.us/index.htmAs pointed out. The WM100 has a higher power line signal and may not need a booster. You will probably still need a phase coupler between the incoming power lines to get the X10 signals to the other phase of the homes wiring. Maybe also do some testing to find power line signal suckers and noise makers.
If you decide to go with X10 transceivers because of the On Off button on them. With the RR501; PAT03 you could have 32 X10 addresses 16 House Codes and Unit Codes 1 or 9.
TM751 will not work RF only.
Modules with a House Code (A-P) dial and Unit Code (1-16) dial. You have 256 different addresses. 16 House Codes and each House Code can have 16 Unit Codes.