I assumed that in the US I would need the NTSC version... Since I am not certain exactly what the 2 standards entail I was simply playing it safe with the NTSC version... So if I am hearing you correctly, if I were to get the 24 bit adapter being talked about on this board right now, it wouldn't matter if I used it in a PAL or NTSC version.. Is that correct?
Basically the only downfall to having a PAL A1200 in the USA is that it probably won't be able to connect to many old tube televisions because the RF modulator will be outputting PAL video. So if you want to use it with one of those old console TVs (like the ones with the built-in record players), you may be out of luck

the video quality of RF output looks horrible, so I doubt you would use that as a long term solution, and composite is not much better, but most TVs will work just fine in PAL mode on the composite input.
I'm going to remove the RF modulator out of my A1200 to make room for an HDMI port anyway...
Anything connected to the RGB port should work just fine, with one exception... I can't seem to get my NTSC DCTV unit working with my PAL A1200, but i'm not sure that's not something I'm doing wrong.
The Indivision AGA 2.0 will work the same for either version of the machine, and you'll probably want to run your desktop in 640x512 PAL mode vs 640x400 NTSC for the extra 100 lines of resolution.
Keep in in mind the the Indivision is not really a 24bit framebuffer, the 24bit thing is _internal_ and is necessary in order to handle the full AGA palette which is 24Bit. There have not been any promises that the new Indivsion will handle anything other than standard Amiga video modes. That being said, you DO still want the Indivision
