I have to interject here, to prevent this chap from going down what I'm pretty sure is the wrong road.
Blower motors and big lead-acid batteries are super for tugs, but this isn't a tug.
25mm or 30mm props on a model this size are a complete waste of time. I had a 32mm prop on my Shamrock, and that's only 28" long and weighs nowt. You need at least 45mm and preferably 50mm to get this thing moving properly, and that's with 3 blades.
If you are going to fit "sensible" motors e.g. MMB900 then use a separate ESC for each and don't even think about lead-acid batteries. Like I always say, the clue is in the word "lead". NiMH is the way to go. There are issues with LiPo batteries in certain circumstances - which I won't go into now.
Having seen Dave Jones' big Perkasa going on one of these motors with 20 cells, quite why anyone should contemplate any other set-up is a bit of a mystery now. He reckons he gets 55 minutes' running time - and Stavros is not known for tootling his toys around the pond at walking speed.
Suit yourself. Works for Stavros.
FLJ
O - I quite forgot Barry Boy's 46" Swordsman, which has TWO Darke Horse geared 785s in it. You need a safety belt just to watch the video of it going.........