I've owned two great Bergaras. But, if I was going to go the custom-on-a-budget route (which I'm planning now), I'm choosing Tikka over Bergara. IIRC there's something about the feed ramps on the Bergara that make them unsuitable for barrel nut style prefits, and the tolerances aren't close enough for shouldered prefits. Tikka, on the other hand, has close enough tolerances that you can spin on a shouldered prefit or any OEM barrel. Plus, changing from short to long action calibers is only $100 in parts.
The downside to Tikka is stock and chassis availability. But, it's honestly good enough these days that you can find what you're looking for. If you want to change calibers, Tikka is the answer. If you want to stick to 243 for now, find a used R700 chassis in the classifieds, and then re-sell and put the money into a Tikka if you decide to change calibers in the future.
If you don't care about budget, I'd go Terminus Zeus with the quick change option.