yo
i'm currently trying to get hold of a 2mb flash simm also. I know that the EMU flash simms aren't half as proprietary as they make them out to be (for example, there are two chips on an emu 1mb flash rom, each with a sticker with a different emu part number on; take the stickers off and the silking shows you that they're exactly the same chip).
I do actually have a 2mb flash simm in my other emu and i'm going to be taking some more detailed notes on the chips etc when i take it apart to have a look - i'll try and remember to post up here when i do.
edit -> forgot to say that i think the soundbank roms are just the same as the flash simms with bigger chips, but i havent yet found out for sure