the one accelerator i mentioned above is adspeed, by ICD, they also make adide and adscsi. If you can find them these are really good because they are very very small.
I had a ram expander in one of my 1000s called the insider2meg by dkb. That worked really well but I had to add a 68000 socket extender to use it. The extender is like a 68000 socket with really long pins. some other accelerators use a similar device.