Beefing up A3000

[B00tDisk]

PCI busboard, as mentioned above.  Maybe consider an Indivision OCS, but then the 3000 has a built in flicker fixer and VGA-out so maybe not.  ZorRAM is a nice way to get lots of RAM, quick.  Substitute your noisy old HD with a flash card.

[B00tDisk]

Please forgive my ignorance, what is the Indivision/GFX card?

It is a scandoubler/flicker-fixer that mounts directly on to the motherboard (does not occupy a slot) that promotes the Amiga's native video output to resolutions and refresh rates supported by VGA monitors.  Additionally, a framebuffer was included in the design and as such it has begun to take on the characteristics of a video card as well.  The designer and creator, Jens Schoenfeld, could probably answer your questions better than I have.  He's a semi-regular poster at http://eab.abime.net/