Re: HK417 accuracy?
Depending on how long you are planning on saving up your pennies, the MR762 MAY BE available by the time you are done saving. HK USA has pushed the release back at least once that I'm aware of and I really haven't continued to follow it all that closely beyond "sometime in 2011." The rifles ARE available elsewhere in the world to the best of my knowledge, so it should only be a matter of time before you start seeing them for retail sale here in the States.
If you want a high-quality, very accurate, piston operated AR-type rifle, I suggest the POF P-308. They allow you a wide selection of barrel lengths, all with high-end Rock Creek barrels (1:10 twist). They will allow you to use many components/stocks/triggers/etc. from the AR-15/AR-10 world to tailor the rifle to your particular needs (this is a HUGE plus to the HK which has extremely limited aftermarket support) and the price on the POF will likely be at least comparable, if not better than the HK.