Alternatives for a UDN2981A
I would:


Replace your low-side shift registers with a LED constant current sink shift register like the STP16CP05
Do away with all the current limiting resistors - just have the current set resistor for the constant current sink
Use discrete (or multi-pack) PNP or P-channel MOSFETs for the anodes, or a high current shift register source (not constant current, just any shift register that can source larger currents).