Gregski... You are doing a bunch of math but are you aware of the amount of weight you're talking about. 100 ah lead acid batteries weigh about 60 lbs each and you want to run six of them, that's about 360 lbs

... remember balance

somethings gotta give, seriously, a bare chassis with motor and controller less batteries would be probably 150-200 lbs all by itself, then add 360 in batteries and a 180 lb rider and you have 700 to 800 lbs that you're powering down the road.
Also, I hate to say it but your math did not take into account the fact that you should never run your battery pack below 35% capacity or they will not provide nearly as many recharge cycles so whatever number you came up with for power/range subtract 35%, sorry.
Check out this guys set-up
http://www.electricmotion.org/ This represents a very nice thought out package.