Rumors never die. Especially on the internet.
There is no need to replace commercial parts with USGI parts. That is just a silly thing that some M1A owners do. They have to justify this silly behavior so they tell tales of inferior commercial parts and repeat rumors. For example, that "soft bolt" problem occured nearly 20 years ago. Also, most of the "soft bolt" stories involve Chinese made M14 clones.
I have owned 3 M1As. All had a mixture of commercial and USGI parts. With many thousands of rounds through them, I had to replace exactly zero parts. I sold the first two because I needed the money, not because they were not excellent rifles.
If you just have to have an M1A, by all means get one. I have one now and I love the rifle. However, if I didn't have one now, I wouldn't buy one. They are expensive and will continue to be so. Magazines are also expensive. Military surplus 308 is getting scarce and the price on it is climbing as well. If I were in your situation, I would stack up 10,000 rds of South African ammo before I even began looking for a 308 battle rifle. The guns will be around for a very long time. The ammo is drying up. Without ammo, guns are just expensive clubs.
For about 2/3 of the cost of an M1A, you could buy an M1 Garand and have it rebarreled in 308WIN and buy a few dozen enbloc clips. You would have an excellent USGI rifle and it would perform at least as well as an M1A.