CDARS program for the first 50 million.
Then I'd buy a sh!tload of individual issue GNMAs each year and ladder it so I am always buying new GNMAs each year.
I'd also own a ton of treasury inflation protection in VIPSX. I'd prefer to own individual I bonds but I cannot figure out why there is a max a person can buy each year and the max is so little.
Buy a lot of munis that are go, not revenue based.
I throw in a little VTI, VWO, EFA, and VNQ and call it a day.
It may not be the best way to go but I'd be able to sleep at night and only have to worry about spending the money.