The disadvantage of scissors jacks is they are designed for lifting, not stabilizing. If the trailer does shift, they tip over easily, especially sideways.
If you go that route as a temporary measure (and I'm not seeing any off-the-shelf, free-standing alternative with only 8" of clearance), you will want to avoid sloping sites, keep most of the weight
on the wheels, and chock solidly. You might want to consider BAL or Anderson levelers for the wheels with integrated chocking function.
As an alternative, a bolt-on installation of Atwood or BAL stabilizers could be swapped onto the new frame when the time comes. It would depend on how much you plan to raise the suspension, of course. Product specs include a working height range.