You will have to start fairly light, but this should move up very quickly and end up higher than your full squat max for reps with explosive transitions. A good way to gauge how much weight you need is to pay attention to the actual time you spend pushing when you come out of the hole. Youre looking for more of a *down, POP, and youre up.* It should feel like you "push" for less than a second or so, which creates enough momentum to take you to the top. If you get more of a constant "strain" to get up, then youre not going to get the same training effect I am referring to.
This will not be light weight for long, and once you get used to using the eccentric to gain more power and are able to actually benefit from it you should notice a dramatic difference in the amount of eccentric force you can load your jumps with and use the added power rather than collapsing from overload.