If it's a babbit-pounder, it's going to take more experience and expertise than the average volume rebuilder will be able, or willing to supply. I'd strongly reccomend going for the machining process to install the insert bearings in the rods. I was in charge of doing that machining on Chevy rods for a big rebuilder in Nashville, and it makes it much simpler to do a good buildup.
Adjusting the oil squirters is also a critical part of a good rebuild. They're not only tasked with filling the dipper troughs, but they need to squirt oil directly into the rod dippers at higher engine speeds. If possible, you'll need to find someone who is familiar with the special needs of these engines, and give him enough time to build it the right way.
Jerry