The MiSTer can do this. It can do MC68020 and will meet and surpass A1200 performance with AGA, and RTG graphics support is in fact there as perhaps the most recent major update. Yes, in 16 bit color and all with very good performance. And it's much, much cheaper (and quicker to get!) than a standalone Vampire. Like a third of the price or something for a pretty complete setup.

https://misterfpga.org/viewtopic.php?t=414&start=25

This should be the install instructions once you have the MiSTer. (the code is closely related to the FPGAArcade RTG support so apparently the procedure is pretty interchangeable)

https://www.fpgaarcade.com/kb/how-to-setup-the-rtg-picasso96...