Surplus .30-06 dried up quite a few yrs ago now. Both Federal and Hornady make Garand compatible ammo and the boxes are so marked. I don't know if these are being sold in Canada yet.
Handloading is a good way to go. Stick to IMR 4064 or IMR 4895, use bullets in the 150-168gr range and ensure that primers are seated below flush with the casehead. The adjustable gas plugs do work. There was a good article on them in the last Garand Collectors Journal. Brownells sells them.
