1965 Special mint sets were the only proof like sets for the years 1965, 1966, and 1967. The Kennedy is 40% silver and has an actual silver weight of 0.14790 ASW. You need to go back to 1964 to find 90% silver in the Half, dime, and quarter.
Be wary of anyone that tries to sell you a "sealed package" as these sets have dry glue that can be easily sealed.