Agreed. For best result, you don't want a pre-fab job anyway.
The T3 is not a round action, and it has a sharp curve down towards the barrel shank. For optimal esthetics and stock fit, you should order a barrel with a 1.200" shank end. The rest is straight forward. We have some great gunsmiths in BC who can mount a barrel.
What restricts you is the recoil lug, these are located in the stock and fit in a notch within the action. It means you are limited as to your choice of after-market stocks, plus you must be exceedingly careful bedding them.