Leafs don't suck, but on a Taco or 3rd gen 4runner, they make it too tall IMO.
FWIW, $2500 to SAS a Taco or 3rd gen is laughable. Try $8-10K to do it right just on leaf springs. Linking it would be even more $$$. That would be regearing it, lockers, axle, steering, shocks, springs, brakes, driveshafts, etc. Ask the majority who does it what they spend. Its normally at least $8000 and they do the labor themselves.
And, a D44 is just not a good axle to use IMO. It limits you to 4.88s or running mismatched gearing. 5.38s up front and 5.29s in the rear. The pinion angle will suck, so it will require a cut and turn to run a single case as well. It also costs more in the long run to build than a Diamond axle would. Yes, you'll spend more building a $100 junk yard axle than a Diamond if you build them the same.
Even a low leaf spring lift will clear 37s easily on a Taco or 3rd gen with a SAS.
Heck, if you have $20-30K to spend on a bad ass, fast SAS'd 4runner, you should just buy mine. You can't come close to building one for that price.
http://www.toyota-4runner.org/sale-...ffroads-2000-4runner-linked-locked-built.html