Thanks for your thoughts on KiCAD but I'm sticking with Target 3001. I am not going to try and tweak some commercial gear either - they do not have the type of circuit that I need to implement.
The final component values are not known a priori - the user decides these and builds up the daughter boards to suit. Then these are connected in series via the motherboard to form the overall circuit. It is also not known a priori how many daughter cards will be needed. The entire system must be flexible without designing a single PCB for the worst case (the greatest number of sub-circuits) possible. That is why I am going for the motherboard+daughterboard(s) concept.
The final component values are not known a priori - the user decides these and builds up the daughter boards to suit. Then these are connected in series via the motherboard to form the overall circuit. It is also not known a priori how many daughter cards will be needed. The entire system must be flexible without designing a single PCB for the worst case (the greatest number of sub-circuits) possible. That is why I am going for the motherboard+daughterboard(s) concept.
