The most compatible Amiga to buy out of the choice of NTSC or PAL is PAL.
However, it will not be compatible with the majority of North American televisions as they dont accept PAL input.
So an Indivision 1200 would be an ideal option, the only problem is that we are expecting the new production run now in the fall of this year (hopefully ready for Amiwest). This is due to the new FPGA chip that is used is currently in constraint.
So an option maybe to get a second hand RGB monitor to use until then.
Hope this helps!