Why IndivsionAGA gets no love is a mystery to me. If A1200 reloaded comes out I hope there will be regular support / firmware updates - otherwise its a no-go for me.
There was an Xtreme driver (I think Ratte wrote it) for Indivision AGA MK2. I cannot remember where I got it, but it I think I can do 1280x1024 256 color, but beware the Lisa gets HOT, I would only use this if you have a fan, further the screen updates are a bit slow. I don't use the xtreme driver on my A4000 as I have a voodoo 3 on it.
The software is amazingly different on the AGA and ECS versions. The AGA verison is almost too configurable.