My advice would be to purchase the rifle. Sounds like a good starter rifle.
Caliber doesn't matter other than I would suggest against a wildcat at this stage in the game. 22-250 and 243 are easy to make and learn to shoot well. Shoot a bunch, try different loads, etc..
When you are absolutely certain that you can shoot better than the rifles capabilities, if it doesn't have the accutrigger, get a replacement and shoot some more. Still not cutting it, buy a prechambered Shilen and screw it on. Then shoot a bunch more.
If you get to a point where patterns emerge as in heat affecting POI or unexplained flyers from your 1/2moa groups, Buy a stock slap it on and bed it. Get to a point that you can't resolve the aiming point due to increased distance, buy a better scope.
If you get to the point that you have the absolute best load for the Shilen, no detrimental stock problems, best scope fit for your application, and you are still not happy with groups........then start looking for gunsmiths.
Running the load to the best of its ability, all else in order but now bored with plain jane yet effective cartridge....Start all over with a wildcat. Only now with full knowledge of what the parent cartridge lacks as far a cartridge design, if anything.
If one were to skip all the other steps, accurizing and AI rechambering a $300 savage would be sort of like balancing, blueprinting and changing the cam in a Craftsman lawnmower.
For what it's worth I have a Savage in 25-06 that has a chamber that is so sloppy in the rear that the cases look bulged above the web. Some equally, some on one side. And it really doesn't care, it just puts bullets where you aim it.