Since you now mentioned the planned use, I can't help but wonder why not buy a factory Ruger #1 as is, and use it? The older guns are often beautifully stocked, and in calibers like a .243 would make a perfect gun for the game you listed.
If you simply want a custom, the Ruger is a fine choice, but an expensive start, since finding one to get the action from wont be cheap. Cheaper than most new actions, but probably around $1,000 for a gun that you'll only use the action.
If you go this route I'd suggest buying a nice one, so maybe you can sell stocks and barrel, and recoup some cost.
