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To use a flat panel display monitor for DPaint use on your A1200 you are going to need a scan doubler and preferably one that is also a flicker fixer. For video work a Commodore 1084S is hard to beat, but if you can find an LCD TV that can also sync down to 15kHz for its vga input (these are sort of rare) it would be good for most everything you want to do with your A1200.
Are you a new Amiga user, or have you used them in the past?
Again, Welcome!