WarpEngine '40 for the A4000 will give you upwards of 128mg ram expansion and a scsi header without taking up any zorro slots. The VT4000 relys on the AGA chipset to do it's magic. A grfx card will do no good for the VT/Flyer environment in adding chipram due to the way the VT functions.
How's that Indivision working out? Might concider on for my A4000D VT/Flyer, providing it dosen't "break" VT/Flyer operations.