Tange "Champion" tubing *IS* 4130 Chome-moly, just like the Surly. The #1 designation means it is the lightest Champion tube set. Tange "Prestige" tubing was heat-treated Champion #1 tubing, so the frame you're considering would likely be just as light as a similar frame built from Prestige tubing, just slightly lower strength because it wasn't heat-treated.
Here's an old (pre-Prestige) Tange catalog, if you're interested:
http://www.os2.dhs.org/~john/catalogs/tange-catalog.pdf
The Surly frame could be any gauge 4130 tubing. Probably a decent frame, but I'd personally prefer the lugged frame if only for aesthetic reasons.