........points.
1) WDH will redistribute 2/3 of the tongue weight off of the tongue. Assuming close to proper setup, 1/3 to the RX front axle, and 1/3 to the trailer axle. No worries about the 350 lb tongue weight limit.
2) A 2001 (and 2002) 4Runner is power/torque limited. As in 183 HP and 217 lb-ft torque. Torque is king when towing.
a) A 2003 4Runner SR5 4WD returns 245 HP and 282 Lb-ft torque. Much more flexibility for most towing needs.
b) If cost is the issue, then a 2001 Nissan Pathfinder comes in at 250 HP and 240 lb-ft of torque. Better than an '01 or '02 4Runner, but not up to the 03 4Runner.
Denny_A