The Howa / Vanguard is very underrated for custom builds and as they can be picked up cheaply down here I assume that's the same in the US. And while they're not as compatible with as many aftermarket parts as the 700, they are still quite well served in that respect.
As for chambering, what about a 6mm-06 in a fast twist barrel for something different?
Gunsmiths in the U.S. usually charge a little more to rebarrel actions that require metal to be cut to metric specs because their tools are normally set up to work in inches, not millimeters.
