I know a lot of sidemount divers prefer to have the left tank second stage be left handed. Most regs sold are right handed. However, there are many regulators that are easily convertible to left handed operation with only a few minutes work and sometimes, no special tools.
Scubapro R390, Halcyon Aura and Tusa S-60 are all the same second stage, just with different branding. They are easily reversable: use a small screwdriver to remove the pin on the right side that holds the purge cover in place, then unscrew purge cover as you would normally. Remove the gray ring, it has a tab on one side sticking into the housing. Then remove the diaphragm. The plug on the left side comes out next--needlenose pliers will fit the indentations on the outside. In the middle, the plug is square. You have to turn it so it's on its side, like a diamond, to slide it out. Look at it and you can see roughly where you are, once you think it's aligned, apply pressure to the inside with a finger.
Then, unscrew the plastic nut on the inlet hose valve body, and remove the plastic washer. A thin 1/2" wrench will fit the wrench flats, hold down the purge button and turn left to loosen. Then, the inside bits can be pulled out as well. There is a small plug in the inside valve part, that will need to be moved to the other hole in the valve body--the one facing down gets plugged, when you switch sides, you have to switch holes. Reassemble on the other side, and viola!
Scubapro R390, Halcyon Aura and Tusa S-60 are all the same second stage, just with different branding. They are easily reversable: use a small screwdriver to remove the pin on the right side that holds the purge cover in place, then unscrew purge cover as you would normally. Remove the gray ring, it has a tab on one side sticking into the housing. Then remove the diaphragm. The plug on the left side comes out next--needlenose pliers will fit the indentations on the outside. In the middle, the plug is square. You have to turn it so it's on its side, like a diamond, to slide it out. Look at it and you can see roughly where you are, once you think it's aligned, apply pressure to the inside with a finger.
Then, unscrew the plastic nut on the inlet hose valve body, and remove the plastic washer. A thin 1/2" wrench will fit the wrench flats, hold down the purge button and turn left to loosen. Then, the inside bits can be pulled out as well. There is a small plug in the inside valve part, that will need to be moved to the other hole in the valve body--the one facing down gets plugged, when you switch sides, you have to switch holes. Reassemble on the other side, and viola!