Why don't you just buy a Savage Model 12 Long Range Precision. It comes in the 6.5 Creedmore if I recall. Mine is a 260 Rem. It has the target action (large shank), has a DBM (the only way I know to get one with the target action), Target Accutrigger (the only trigger I've set higher than the factory setting).
With the heavy no taper barrel you can shoot non stop and not overheat. As you might expect it is very accurate. To keep things interesting, a friend and I (he has the identical rifle) - have taken to shooting golf balls at 800 yards. It takes several shots but we hit them.
For hunting, I prefer the 110 long action, staggered feed (older, flat back actions), & wood stocks. Why? Usually can be purchased cheap - $200 to $300. I enlarged the barrel channel for a varmint or light varmint/heavy sporter. Bolt head can be changed, so, build what you wish.
For prairie dog, bench, etc shooting - prefer to build on single shot actions. A little stronger because there is not magwell cut out.
Factory 3 screw triggers can be tuned rather easily to 2 lb if you wish.
The newer right bolt/left port or dual port large shank actions are great to build on as well.
Model 10 actions seem to be harder to find in my area. But for the 223/223 AI cartridges, these work rather well. There are some 110 actions that came from the factory as 223 magwell too. So, don't turn these down as well.
Okay, a little more. I'm okay with a mag system like the 12 as I would like to shoot targets and such and then possible put it into another stock for hunting. Most of my hunting will be accomplished by the 6.5 Creedmoor. I do like the 300 WSM cartrifge too, so if the bolt head can be replaced that is a plus. I don't think I'll need a long action on this one. Shorter cartridges like 6.5 Creed, 6 br, 22-250 and at most running a 300 WSM are the goal. I do have a 116 BGH longaction and I run a 6.5x55 through it for now if that helps.
One issue, accutrigger? I don't know if I want to keep it. I now see Timney making a trigger for Savage accutrigger replacement. So I like the idea of trigger options. That's probably my biggest concern in the build. 2nd would be changing calibers, is it as simple as changing bolt heads on all of their actions? On rem's and others you have to open the face or get a custom bolt. So the savage seems more attractive for versatility.There are plenty of stock options so Savage is looking lore and more attractive to me.
Again, trigger flexibility, and bolt head most important. Some may have not seen the news on a Timney trigger for Savage yet, so any experience in that helps too.
Is the 10 or 12 the best action? Why if you have played with both?
I would not trade out my Accutriggers for any other. They are basically perfect. You never know when the gun is going to go off and it takes very little to make it do so.
As to bolt heads. You can buy whatever parts you want direct from Savage (you have to send them a letter saying you will not hold them liable if you blow yourself up).
You can then mix and match bolt heads and barrels all you want. (You need a barrel nut wrench, barrel vice, go and no-go gages and some level of mechanical competence.) I can turn my 260 Rem into a 270 WSM in about 15 minutes including bolt head swap out.
Savage also sells just a target action but that is a single shot (though it would be the stiffest Savage action you can buy). I think it is a better deal to get the LRP as you get a nice HS Precision stock with aluminum bedding block, DBM and heavy target barrel in 6.5 Creedmore. I don't see much difference in the rest of the actions Savage is selling today. You have 3 choices - long action, short action, target action. The parts are interchangeable amongst the same length actions so they are basically the same.