Did you order a 7mm barrel blank, or one chambered in 7-08?
If you're going to go with a Savage (either Target action or a repeater) you should have ordered (or change your order) to a pre-fit. No reason to do it any other way for a Savage, unless you want to have it fitted to the action without the barrel nut system.
If you're going with "other than Savage", just get the 7mm blank.
Let the smith thread it, ream it, headspace it, and fit it to the action properly.
I shoot a 7-08 with VLD's (162 Amax) and it's a good choice. But if you go custom, the barrel can be throated long and chambered tight for VLD's, even to a specific bullet if yo so choose.
If you go custom, find a smith and get your action ordered (usually the smith will do this). Get your place in line...that way, when the barrel ships, he should be ready to go.