>...i dont even know how much/how im going to use it unplugged
seems to me that if you don't know how much you will use it unplugged, you're not very likely to use the 'portable mode' very much, ie. you will access to AC power most of the time.
i would forego the dual-bay getup and even for the time being, the second spare battery (unless you get some sort of discount doing this now).
btw, a run-time of only ~1.5 hours per battery is not very good, imo.