With what you purchased, you can not zone the chime.
Cliff Notes version of what Brian said.
This will get you working.
1. Set the TM751 to "A" house code and plug in to an outlet fairly central to where you want to mount all the motion sensors.
2. Set the chime to House Code "A" Unit Code "1"
3. Put batteries in the MS14s. They will default to HC "A" UC "1". Leave them that way for the time being.
4. Avoid mounting the MS14As DIRECTLY to metal, it really knocks down their range.
5. Experiment with the mounting. Either way you described will end up working. Try to avoid pointing the mounted motion sensor directly at the sun, or a bright light. It makes them temporaly blind to movment, so mounting higher and pointing down may be required if you must point them towards rising or setting sun.
Read on forum or here:
http://jvde.us/x10_troubleshooting.htm , about the down side of X10. Namely: Phase Coupling, Noise, and Signal Suckers. You will probably run into these problems but they (usually) are not difficult to solve.
Now go forth, X10, and doobie not.