The car jump starter is a non-starter (excuse the pun). They are not deep cycle type so you would kill the battery in no time if you used one to charge lipos and took anything more than maybe 1/3rd capacity out of it on a regular basis.
True deep cycles are the only type of lead acid that can be deeply discharged on a regular basis without damage.
Personally i just charge several (eleven usually) batteries at home on a high output charger and take them to the field. This is perfectly feasible if you are flying small to medium size models but gets cost prohibitive if flying larger electric (which is why I'd go gas if i ever did the big stuff again).
I'd get a DC charger and a AC to DC power supply. That way you have your options open for field charging should you ever want to. In any case all the top chargers only come in DC type.