Whatever action you choose, it would be more economical for you to find a custom rifle already made. You never get the full Return of the money sunk into a custom. It is best to let someone else eat that depreciation.
Honestly if you really want the most bang for your buck buy a Tikka T3 hunter in 6.5.
If you must build a custom, look for a rifle that has already been sporterized. The donor action will be much cheaper
