There are a few fast ram boards available. My 1st a1000 had an insider2meg board that worked really well.
The best bet for cpu is actually the 14mhz mod you can diy. It doesn't speed things up double and it can cause problems iirc with floppy but for some software there can be a little boost. There was one 14mhz mod I saw that had a switch that could be hot switched.
the mega midget racer
http://amiga.resource.cx/exp/megamidget has been used succesfully in a 1000.
amiduffer beat me on the mega midget, the link has some info on it, its pretty rare though
icd made a 14mhz 68000 accelerator too
