Pass on the indivision unless you are hooking up that 1200 to a large TV. I would take that same money and get a good condition Dell U2410 monitor on ebay. I have seen a lot of new ones lately showing up for $120 or less.
That monitor will display all the modes the amiga offers for games in a great screen through VGA native, you ust need the 23 pin to VGA adapter that all 1200 and 4000 came from, you can find those as well on ebay if you dont have one.