From everything I gathered and when I spoke with an individual at CMP, the loaners will only be differant in the type of stocks. Some may have USGI, others may have mixed wood, etc. The parts on most of the rifles are mixed as CMP only promises the receivers will be of the brand you purchase (unless you get the service, correct grades, etc.)
If you look at CMPs website it's evident that pretty much everything they have is drying up. I sent in my paper work a few days ago and still haven't received order confirmation. But they are indeed very busy.
My advice, if you have the money, purchase the service or higher grades (if available). If not, any M1 from them is better than none. Like everyone around says, they're only going to get harder to find. I'll try to post some pics of mine when I get the chance. They should be up sometime around Tuesday. Hope this helps.
Billy