I've got some 50nS EDO 64MB SIMMs here - standard height, double-sided. They're yours if you have £30 spare.
I've never been able to get them to work, but only because none of my accelerators support them - they just appear as 16MB modules in everything I've tried them in. I've never tried them in anything newer than an 030 accelerator, a CS-PPC (which doesn't support 64MB modules, unlike BlizzardPPCs) and a P200 PC.
I have no idea if they'll physically fit, but they're the same size and shape as any double sided 8MB or 32MB SIMM I've seen.
