The RGB to S-video adapter from Amigamaniac would work perfectly to connect a PAL A1200 to an NTSC TV.
not quite true. the Narmi circuit that Amigamaniac uses (AD724 encoder chip) is designed to allow both PAL and NTSC display, however, you cannot correctly display an out of region Amiga correctly on a different region TV, for instance, a PAL Amiga will not display colour on an NTSC TV as the colour burst frequency is different. The purpose of the PAL/NTSC switch on the Amigamaniac circuit is so that the adapter can be used anywhere in the world as long as you use the correct region Amiga with the same region monitor/TV.
If you want freedom to display any region on a TV then you would need to buy a multi region TV that will display all formats like for example...
http://www.world-import.com/Sony_KLV-26T400A_Multi-System_LCD_TV.htm edit... may be a bit expensive but it works perfect for all displays
