This one's mostly for V2 users, since there's already a Speccy core for V1 hardware - but I've ported the MiST ZX Spectrum core to TC64 - see http://retroramblings.net/?page_id=1880
There's no direct SD card or HDF access as yet, but floppy images, tape images and snapshots should work.
As usual the C64 keyboard and joystick is supported.
(I also noticed that the Speccy core for V1 on the Wiki seems to a dead link - though it can still be accessed using archive.org's Wayback machine - so maybe this core will be useful for V1 users after all...)