Ignoring the technical issues, it is a bit pointless to put workbench in EPROM. If you want silent operation and fast Workbench access... get an A600/A1200 and a PCMCIA flash card!
Looking closer, just for Kickstart type stuff, I am not 100% sure if the A500 motherboard can take larger EPROMS. You'd have to create a harness to the Gary chip / 68000 to access the extra ROM.
The A1200 and A4000 can both take (and utilise) 1Mbyte EPROMS.
Redskull once did an A500 flashROM adapter that is available as schematics on Aminet.
