For overland use, a 2.5" Dobinsons or ICON system with springs rated for your actual gear weight is the community-standard answer — complete fitment, load options, and rebuildable dampers. "Best" truly depends on constant load: a stock-weight truck and a bumper-tent-drawers truck need different spring rates within the same kit family.

A shop bills 4–6 hours for a complete kit; a capable home mechanic with a spring compressor should plan a full day. Rear leafs are straightforward; front coilover assembly is where the time (and the caution) goes. Add an alignment appointment the same week — non-negotiable for tire wear and tracking.

Payload and tow ratings don't legally change, but capability character does: load-rated springs actually improve how the truck carries tongue weight and cargo versus sagged factory springs. Watch driveline angles when towing heavy with taller lifts — another reason the 2.5" zone is the sweet spot for working trucks.

Above roughly 2.5" of front lift, aftermarket UCAs restore caster and ball-joint geometry — steering feel and alignment specs come back to factory-right. At 2" or below, stock arms usually align fine. Many complete kits offer UCA options; if you're at the 3" line, add them.

Spacers raise the truck but change nothing about spring rate or damping — fine for looks, wrong for loads. A real spring/shock system costs more because it's doing the actual work: carrying your gear without sag, controlling washboard, and surviving years of it. For an overland Tacoma, yes, it's worth it.