I went through something similar lately when looking for an all around rifle for use at home and, hopefully, out west. Also went through the same when getting a longer range training rifle.
For me, it was hard because it seems like some decisions are in conflict or there are complications that get in the way.
I want to learn to shoot long and I find a light rifle harder to shoot. But I've carried a 10.75 lb rifle around too, and I don't like that either. So there is the weight decision to make that balances what your personal desires and priorities are. You have the Christensen on the lighter side and the Sendaro on the heavy side, so you are in the same spot as I was. (I was looking at a Weatherby Backcountry on one hand, and a Remington 5r on the other, as concerns off the shelf guns).
Then there is the 'which will shoot better out of the box' question. Spending nearly 2k on a production rifle without a great deal of confidence in what you are getting kinda scared me, as I've been burned before on rifles, though they were not high end productions like your considering.
So personally, the choice came down to
1) Custom...by no means an absolute guarantee of a tack-driver, but pretty certain and you have a good bit of recourse if things don't go well. The downside was the wait time (my local smith could not even give me a time-frame, but at least 6 months wait, maybe longer, to even start). And of course, the cost.
2) Buy a rifle that has an action, but also the stock and maybe the trigger, that I liked at a much lower cost that has a reputation or even a guarantee of decent accuracy (not that the guarantees are iron clad at all, but it's better than nothing and gives you some recourse if you want to try and pursue it). If it shoots for you, great. You are in business. If it does not, you have the doner action you need for the custom route anyways. If it already has a stock you like and mayyybe the trigger, you are even more ahead of the game.
Ultimately, unlike previous endeavours, I got lucky. Both rifles shoot accurately enough for my needs, so other than a few little things, there is little to do and I saved a bunch over getting a custom rifle. But if I had had to go the custom route, I could have.
The only downside to going this way is that if you KNOW you want a custom gun, you can buy the cheapest thing off the shelf and toss everything and go and possibly save a couple hundred in the process vs picking something a little more high end to start with. But for me, it was worth the risk and, happily, it appears to have paid off.
Good luck with your decisions. I think it's a lot of fun to go through. Frustrating some times, but it's a lot like creating something just for yourself.
