Range depends on many things. Your weight, the pavement, if they are hills, wind etc. The meepo 4.4Ah battery is sad to be sagging after you reach around 50% of the capacity. In this regard are the Lipos you linked to better. But you have to take care of them maybe more than Li-Ion batteries. My advice would be to get a decent battery and from there on you can replace and upgrade your parts surrounding your pack. Edit* I saw that the app you were using calculates the range with 25Wh per mile, this is very conservative. But I think, if you take the sagging in account, this is what you get in range with a decent performance of your board, after that it will likely start creeping.
So I think I mind as well purchase a Li-Ion pack. Did you make your pack? I am not sure on the size pack I would like, I am thinking 3p or 4p. Do you have a recommendation, it seems all I need is 3p, 3p should be enough. But a 4p pack is only $50 more. Let me know what you think. What is the range difference?