Re: remington 700 action
willsnipe has a couple of stainless LA 700's for sale currently, I think one of them is a mag bolt face as well.
If you consider that cost of that vs. a full custom it's a little cheaper, but not a huge amount.
He might has some regular blued actions, I can't speak for him though, it's worth sending him a PM.
If it was me (and I priced this out and did the homework) I would take the Rem 700 LA and have one of the several excellent gunsmith members on here (wnroscoe, robert gradous, 300sniper just to name a few) and ask one of them to blueprint the action and chamber the barrel.
If you have some mechanical abilities and can bed the stock yourself by all means, go for it, it's not hard.
Also, you need to decide on the barrel contour and what bullets you plan to shoot with it. If you bought the long action I'd personally chamber it in 7 WSM or 7/300 WSM and forget the 7 RM just to avoid the belted case. Personal preference more than anything else.