My Amiga 1000 is stock. I've only really though about adding A500 external HDD, and maybe a kickstart ROM mod. I'm not too sure about accelerating it, you still only have an OCS Amiga at the heart, so a lot of the demanding software still wouldn't run. So what is the benefit of a faster CPU in it?
Your A1000 will be able to do up to 1390 x 1024 x 32 via RTG. Any software which already targets RTG should be able to make use of that immediately.
You’ll also have 128 MB of FAST RAM.
I’m given to understand that eventually it might be possible to do 1920 x 1280 x 32. We’ll have to wait and see, but every core update makes it better and better.