One thought on the 2 chargers is - if one dies - you still got the other - if the other one dies - your down until you get it replaced. I have a few cheap RS wall chargers and one really good Pulsar charger that does one at a time and I'll charge 3-4 in a row theday before and it's no problem doing one at a time. It doesn't take that long maybe an hour and a half or 2 per pack.
I also have one of these boats that I got off ebay - what this guy did is buy the 775 and later updated it to the extreme - maybe buy the 775 and try it - then pick up a cf prop - then later pick up a xxx... this way you lower you cost - in the beginning, and have something to look foward to in speed as time goes on - just a thought.