Just one more thought.... I have a PL6 and it will display the input voltage and current for you. (The power supply output) I think you must be actively charging for that page to be available, but that's really the only time you need it.
Again, the power supply you need is really a function of the batteries you want to charge. How many cells (voltage) and what charge rate (amps) are you going to charge at. But since you are just getting started this maybe still in question. I too am a fixed wing guy and I do not know what type of batteries are in a high end heli... My guess is you want to be able to parallel charge a few of those batteries (I'm assuming lipos.)
I just have this power supply with my PL6
The biggest batteries I have are some 4S 2650 mAh and typically I'm just charging a bunch of 3S 2200 mAh batteries. So far it is keeping up with my needs, but the PL6 can do much more with a more powerful power supply.