I don't have my books in front of me to see what toyota spec is for each numbered size, but I will tell you that his spec is a pretty wide spec. Oem toyota bearings should be available from any dealer. I have the part numbers, but again, I don't have them in front of me.
Your machinist maybe telling you your over thinking it for a few reasons. One is that he wants to line hone the mains, re-do the rods, and size the crank all to fit an aftermarket bearing so as not to fool with select fit bearings. The other reason could be that he is in the same trap that most every machinist in the country is in, and that they are so used to re-building older american v-8 motors, that their entire thought process revolves around the fact that you just grind and hone, install some bearings and its good enough.
One other problem is, most machine shops will refuse to do high tolerance work. Most shops just want to crack open a book, have the book tell them what size to make everything. Then they just get everything close enough to call it good. With that type of common rebuilding in a production type shop, you will get clearances all over the place, but is still considered within spec.
Now about using std size bearings on a select fit system.... for one thing, there is no std size in a select fit system. In an aftermarket bearing such as clevite, there is a std size. BUT, each manufacture will spec in their book what std size is, and it will vary slightly between manufactures. But all these manufactures STD sizes all revolve around the toyota range sizes.
If your rods are truley out of spec, then they will need re-sized. If you are going to use ARP bolts in them, then they will need resized no matter what. Now, you are looking at having all the rods the same size. So you might as well set all the rod journals on the crank to the same size and just use a clevite rod bearing. If your main caps need line bored or honed, then again, you are looking at having them all one size, so you might as well set the crank mains to one size and just use a clevite main bearing. Now if none of this "re-sizing" is needed, then use the toyota bearings.
One other thing to think about is, if you are going to use arp bolts in the oem rods, and will be resizing them, the cost of the arp and the cost of the resizing of the oem rods just paid more than half the cost of new eagle rods, which are already set for a clevite std size bearing.
Believe one thing, you are doing it right, and if more 7m owners would, it would have a much more acurate reputation.