I have flown a 3.5 hour leg with it (on full brightness) and there was 7% charge left when I reached the destination. Pretty impressive really!
With regard to the charger plug - just get a good quality one and you'll be fine. Look for ones that say they are suitable for 28V as this will cover all possibilities. I bought a twin 2.1A one which is tiny (no bigger than the body of the plug itself) and it works fine. It came from Expansys.