TPIC6x595 family only goes up to 350mA/channel for 8 channels with the TPIC6A595, and I imagine good heat sinking.
It looks to me like the same capability as the M54564p, 350mA/channel, but as a shift register.
I think what you want is ULN2803 for straight buffering.
http://www.ti.com/lit/ds/symlink/uln2803a.pdf