The problem between a PAL machine and an NTSC machine is that they run on different clock speeds, and the PAL machine even has a separate clock just for the graphics. (2 crystal clock generators in the machine, instead of one for NTSC) Therefore you can't use an NTSC machine, nor convert it, unless you modify the computer extensively.
There are PAL 1200XL's, but they are rare. They can only be found in Europe, and even then they are scarce.
You're better off buying an 800XL/65XE with PAL signal. The only real difference is 4 function keys that you won't need.
The suggested program FIX XL, aka XL FIX, aka Translator, is a program that makes old 800 software run on an XL type machine, by loading the OS for the 800 into the XL, and running from there. This is NOT a fix to make an NTSC machine run on PAL.