The Taga 2.0 bikes come with mechanical disc brakes up front, activated via a single lever that splits the steel cable to both sides. The rear brake is a drum brake on the non-electric versions, a disc brake on factory motorized bikes, and is sometimes a rear drum on aftermarket setups as well.
Upgrading the front 2 brakes can be tricky for several reasons.
1. The dual setup is not as common, (activating 2 calipers with one lever)
2. Being a 3 wheel bike, there's a "parking brake" feature built into the levers.
3. Rear brake style varies.
The easiest solution to improve braking is installation of the Juintech hydraulic brakes up front. With any 3 wheeled bike most of the braking function can be accomplished with the front two wheels. In fact, some trikes don't even come with a rear brake! The juintech calipers allow you to leave the stock brake levers and cables in place, making for a quick 5-10 minute installation, whilst adding some of the benefits of hydraulic brakes.
The next best would be finding a fully hydraulic system with a t split allowing operation of two calipers, but currently they're not carried by many and hard to find. It's also more complicated to install and get hose lengths, etc correct. Based on slower speeds of the Taga bikes, it's likely not necessary.