Re: A1200 graphics
It really depends if you want to stick with a desktop case, or a tower conversion. Obviously a tower conversion will open up a lot of graphics options.
But if you wanted to stick with a desktop case, then you do have the option of probably the best Amiga specific graphics card that was ever made. The Blizzard BVision. But this only works if you have a Blizzard PPC accelerator for the A1200 as it connects to the local PCI expansion bus found on this accelerator card. More details
here.
If you instead go for a tower conversion you instantly open up a lot more possibilities. An expansion board such as the Mediator, which adds PCI slots to the system, will then allow you to use certain PC graphics cards with the Amiga. These are mainly the old Voodoo 3 and higher graphics cards.
This page lists all compatible graphics cards and other PCI cards.
If you were to opt for a Mediator expansion board, then make sure you get the later LT, LT4 or SX board, because the original Mediator PCI 1200 doesn't work with the Apollo 1260 which you have, but the later boards do.
There are also other makes of busboard for a towered A1200. Some others also offer PCI slots, but are not as good. While others expand the A1200 so it is more like a big box Amiga with Zorro slots. This would then allow you to use an Amiga Zorro based graphics card, but this could get very expensive considering how rare Zorro cards now are. Better to stick with PCI if possible. You can look through the available busboards
here.