Re Timing:
Using the above mentioned chips or similar, you can shift at your leisure, just get it all done before next refresh. I would not time the shift, it can be done in about 5 cycles per shift 8*8*5 ~ 200 and a 200 cycle tsak is not a big deal. Then use a timer for the refresh and set a flag for the main loop to indicate shift is due.

Have fun,

Erik

PS I am just now working on a color LED display 16*112.