That's the plan!Increasing N fertility and lowering soil pH can be accomplished simultaneously by using an ammonium-based fertilizer. Like you said, sawdust can sponge N but then releases it slowly as decomposition progresses, so it's a pretty ideal amendment if you're not opposed to using chemical N fertilizers.
I registered with http://www.getchipdrop.com but have 2 loads of chips from my property and a neighbor's. I also use them as a mulch on my planting beds and around the trees in my lawn.You might check into some tree companies, they dispose of some trees by shedding. Rather than dumping, they might help you out for helping them out. Saving dump fees is always good. Got about 200 yards from truckloads of dirt that way.