My experience is that because of the cost of parts, especially from the factory, you will save only a few hundred dollars rebuilding a Toyota engine yourself over buying a rebuilt unit. Also, many do-it-yourselfers scrimp in areas such as engine honing; these days, loading the top of the engine to simulate the weight and force of the head and studs while boring and honing is highly recommended, but most home rebuilders aren't equipped to do this. I say let the pros do it. And you'll have a warranty and recourse if the rebuilt unit has problems.
I've heard of all kinds of oils for break-in. Red Line still recommends using a dino oil for the first 2,000 miles after a rebuild before switching to synthetic, because of the wall glazing issue. Those engines that use synthetic for a factory fill, including Porsche and Chevrolet Corvette, have special (expensive) proprietary honing procedures done at the factory to prevent glazing. My thought is to use a good dino 5W30 to start, change the oil and filter at 1,000 miles, refill with fresh dino, run till time for the first oil change at 3,000 miles, and then change oil to your favorite synthetic along with the filter. And drive gently until that 3,000-mile mark.