I say Borrow an Amiga with a Genlock that has S-Video OUT and record it to a DV camera that has S-Video input. this way you preserve the Animations looking spectacularly accurate. Then later if you wish to degrade them to AVI or MPEG you can do so.
Just boorrow.....those animations must be preserved at highest quality.
But for best preservation.....put them on WInUAE and convert the frames of all animations into GIF frames if they are 256 colors or less......if they are HAM or HAM8, then save each frame as PNG or some uncompressed 24bit picture format............then later you can always recompile them back to an Amiga. Heck.break them up as IFF frames and save that!.then later convert to GIF and 24bit.