Brownells sells some kits with straight spring wire. The only tricky part will be putting the proper bends in the spring...especially the 90 degree bend. The trigger spring in my pre-accutrigger Savage has a 90 degree bend in it where it fits into the adjustment screw.
However, much to my surprise, when I completely removed the trigger spring from my rifle, the pull was still about 8 lbs. Apparently the previous owner had been over zealous in setting the over travel set screw too close. I was essentially pulling against the set screw. Doh!
After doing to light polishing at the sear and setting the trigger up correctly, it breaks cleanly at about 4 lbs. Perfect for a hunting rifle.