777
The stock savage trigger on the 200 was a 2 screw trigger. It was adjustable. Taking a 1000 grit file to the sear mating surface was enough to clean it up in a couple swipes. The trigger return spring was easily replaceable by the owner. The axis trigger required a bit more work. It was a total redesign.
The 200 had less finish work, but at the heart of it, its still a 110. I can generally take a stock 3 screw trigger (only difference between the 2 screw and the 3 is a set screw for adjusting sear interface) in about 1/2 an hour with a lot of testing down into the 2.5 lb range (safely). As far as I'm aware, and this may have changed a lot since I last looked into it, the axis required cutting coils on the trigger return spring and it wasn't as adjustable.
If you're going for straight upgrades, anything used for a 110 can be used on the 200. The axis requires a different stock inlet, and I'm not sure you get the same selection of stocks. You could probably drop 900 on a custom inlet stock from manners and the like though.
I dont see a reason at all that you couldnt use the axis as a base for a build, especially if a good aftermarket trigger is available (look towards the rifle basix or timney there). With the stevens, it usually came with a pretty flimsy stock as well, but you could use any take off stock for a long action, stagger feed savage. Folks sell the take-offs cheap. I'm not really sure how much aftermarket stock support is out there for the axis. Last time I looked into it, the axis had only been out about 6 months.
I know there are aftermarket triggers for the 110 that get it measured in oz, not lbs. There are plenty of aftermarket stocks for the 110, triggers, drop in barrels (different thread on the axis), recoil lugs, trued barrel nuts, and action truing services out there for the 110. Been a LONG time since I checked on the axis. If you hop over to savageshooters.com, you will probably find all sorts of info for accurizing and improving the axis out of the box that will be MUCH more up to date than what I could give you.
I do know that converting from 223 to something like 308 is a traipse with the 110, its a bolt face swap and a barrel swap. I dont know if the axis has the same floating bolt face design that makes that swap so easy.
Also, looking at pics, it appears the axis doesnt use a sandwiched recoil lug like the 110, it uses an insert in the stock more like the ruger american (except 1 vs 2 of them, and not a v-block design)