Yes you can buy in the US, you just have to arrange it with your broker, if they offer the service. If they don't find one that does. ie TD waterhouse or Etrade etc.
Looks like the final action on friday did correctly tell of a short term top. What happens over the next day or two will be important in telling if this top last days or months. $40.46 silver is the danger line. All in cash since this morning. I have a bid in at this price and if it continues through and down, I close and am done.