98-11 Ranger 4wd uses same SLA IFS suspension yes.
Rough Country and Superlift make drop bracket lifts for the Ranger that can be adapted to your Sport Trac
To match the 6" drop bracket lifts in the rear you would want to convert your sport trac from spring under to spring over. This is where a Ranger is different then an Explorer/Sport?sport trac, the ranger already has its leafs over the rear axle, the explorer does not. So you can gain 5" of lift simply by welding on perches and moving the springs to the top of your rear axle
Also long travel suspensions from BTF and LTI, as well as a few others are also available
Blue Torch Fab
Long Travel Industries
I vote for a +2 Kit from LTI, ditch the torsion bars and convert to coilovers all while adding 2-4" increased track width.