Any opinions on the advantages/disadvantages of these different Reynolds steels for a fully loaded 700c rig for riding mainly on paved roads (Europe, USA, OZ, NZ)?
I'm 154 lbs, up to 40 lbs of gear mostly on the rear rack, 28/32 mm tires...

The difference in price from the cheapest to most expensive is about $500 which is irrelevant.
I'm obviously going to discuss this with the builder before ordering - but you guys' wisdom would be most appreciated as well

631 tubing
631 oversize tubing
725 tubing
725 oversize tubing
853 tubing
853 oversize tubing
853 Pro Team tubing