Electrical Crossover with "Major" Brand Bikes?

[thebeav]

I have a 07 EC300 that the previous owner pulled most of the electrical off. Only things left are the tail light/brake light, ignition map switch and a kill switch.
They left the connectors taped up (thankfully). I recently added an Acerbis headlight without any issues. No switch, just on when the bike is running.

I want to add turn signals/horn to get the bike plated.

I want to purchase electrical parts on the aftermarket. Shopping at Rocky Mountain ATV, BikeBandit, etc. is worthless as they all cater to the "big four" (Honda, Suzuki, Yamaha, Kawasaki). There are no GasGas options.

I have 2 questions for you smart guys out there.....

1 - Is there a crossover brand to use for GasGas electrical items?

2 - Is a battery/voltage regulator required (no electric start required)?