I'm looking to do the same thing caliber wise, and I'm looking to stay with the same actions for the reasons you cited. I prefer the Tikka's, but they can be a tad short on COAL for the 280AI if you want to twist the barrel for heavies. Not that such a rig won't still have a lot to offer, it's just held back from all that it could be.
Up until not too long ago, there were some left hand, SS 700 actions with standard bolt face available on GB for decent prices. I picked a couple up. Paid less than $500 each.
