A 540 won't work with Taigen or HL control boards. They draw too much amperage. They also won't fit because they are too fat. You'll need to stick with motors that have the same diameter as the stock 380s (or smaller). That leaves you with 380s (stock size); Speed400s (same size as 380s but more powerful) and 480s (aka "long can" 400s because they are the same diameter as 380/400s but about 25% longer). The 480s only fit in your wider tanks and would probably fit in the Leos. I don't have a Leo; so, don't quote me on that.

Exactly what makes the difference between the 380 and the 400s is something that I'm not clear on. I think it has something to do with the turns in the motor. But, from experience, I can tell you that it gives a noticeable increase in torque and speed, especially torque.

Note that (from everything I've read and seen) you also need to stay with brushed motors (not brushless...how the stator is built inside the motor) if you're using Taigen or HL electronics.