For testing the ignition,any 12 volt battery will be fine.
Hook this 12 volt battery to just the ignition. Leave everything else unhooked foir now.
Check the timing and for spark. Fuel delivery is very important, no fuel, no run.
With petcocks OFF, unhook fuel lines, run to a catch can, turn ON fuel. Fuel should run out of the line. If not igure out why, Maybe no fuel in tank.
If fuel flows out of line, Rehook to cabs. Open carb float bowl draian, turn ON fuel. Fuel should flow out of carb drains. Is not fine out why. p;robably the float valves are stuck shut. Plugged with crud, Floats not properly adjusted.
Might have to read through the carb guide and clean the carbs.
Once you verify fuel flow and get spark at the right gtime it should run. Once rfunning with the battery you can then try hooking the PMA to the reg/rec and then from the reg/rec to ground and basttery positive. Start bike and check for violtage at the battery terminals. At idle it may not read much more than battery viotage. Aound 12 t0 12.5 volts. Rev engine up to about 2000 rpms. The battery voiltage szhould rise up to areound 14.5 volts. If reved higher it should not go above the 14.5 volts. If it goes higher your reg/rec or grounds need checking.
Once you determine if the charging is working then you can start adding the other things. The head/tail brake lights.
Doing it this way insures you have the basics right before you add more complexity to the system.
Once you get it working with the battery and charging system you can ry swapping the cap for the battery. If evrything is right, then it should run with the cap.
One thing to remember is that your main 20 amp fuse goes between your power source, the PMA and Battery/cap and the main switch, After the main switch you can run the power to your other fujses. One fuse for just the igniktion, A 7.5 amp should be fine. One fuse to power the head/tail light. A 10 amp works here,
A 10 amp fuse to send power to the brake light swirches. If you have a elctric horn, yu can run it from this fuse.
If you want to add turn signals you can add another fuse.
Fuses should be placed as close to the source of power as you can. This protacets as much of the wiring from the fuse to the item as it can.
Leo