Tom, my projects are normally limited to things I can't buy as I've also found that the prices for some of this stuff is less than I can do it for.
However, I think Stan had the additional output loads in mond with the transistor and MOSFET versions above. Those are not CA - CC interchangeable by jumper selection, they would need separate PCBs for CA or CC. I am not sure of how much extra load they can handle, I'll have to look that up on the data sheets. (I don't know (or completely understand) all the components like Stan and GRJ do.)
If the application is to control track power, I'd go with a 10 Amp relay module...less than $1 per relay with free shipping from Asia. So, for example, 6 of the 8 relays in this 8-channel relay module could switch 10 Amps to R, Y, G or each direction.
These relays have buffers on the inputs so can fire at about 1 mA which can be supplied even by the 4070B version of your controller board. I notice the suggested other controller module can drive just under 1 Amp per output. Not clear if this would be enough to switch track power for block or traffic control.
As I understand it, the other controller module can only drive DC loads whereas the relay module can switch AC...again, if the application is to control track voltage.