I think the best would be a transmission jack, but few people have them (you can rent them). The cheap hand crank up ones work OK, I have one and lift our 440ah bank into place under the van with it.
Next best, IMO, would be a floor jack. Little floor jacks are very inexpensive, but don't try to lift anything big with them.
Scissor jacks would not really be a choice I would like because if the box is hinged down, the jack will likely need to move as the box is lowered and scissor jacks don't have wheels like trans and floor jacks do, plus scissor jacks are very unstable side to side and with high risk of tipping over if stuff moves.