Easy enough to do.
http://www.odcmp.com/Services/Rifles/m1garand.htm
Eligibility requirements: http://www.odcmp.com/Services/Rifles/eligibility_requirements.htm
For a first time buyer, I sould suggest that you wait until Service Grades are available and get one.
Now if you are an experienced gunsmith, I would suggest you get a Service Grade barrelled receiver and a kit from http://www.northridgeinc.com/m1_garand.htm (never mnd the description, the kits are $200 minus barrel) and put them together. No special tools needed at all.
I knew about getting them from odcmp and eligibility. I didn't know about the other info you gave me, especially Northridge. On the barreled receivers, which is better Springfield or H&R?