long story short for direct fit match for match 01-02 trac is your best bet for the suspension/drivetrain.
as for cross compatability per part you mentioned
rack and pinion: 95-01 4 door explorer/mounty, 01-03 2 door explorer sport, 01-05 sport trac
gas tank: 01-03 sport trac (21 Gallon), 95-01 4 door explorer/mounty (21 gallon)
four wheel drive (transfer case, and front axle components): 01-05 sport trac, 01-03 2 door explorer sport, 95-01 4 door expo/mounty
rear end:01-05 sport trac, 95-01 4 door expo/mounty, 2 door expo sport
catch with the rear end is your rear end is drum for a one for one swap use those years list and find drums if you're couragous go for the newer rear ends with discs.