Isn't there a board that allows you to use SIMMs instead of ZIPs?
There is also this:
http://www.amigaworld.de/hardware/simm-zip-ram-adapter/Not sure the availability and it is for the 3000 not bridge board. So not sure if it would work with that. Biggest issue with it would certainly be space next to the 386 with the board and SIMS, as well as layout of the Zip sockets
But, of course, if one could be made for the 3000 one could be made for the 386 bridge board. Just a matter of the time, money and expertise I would think
