Where can I find current price of US Treasury Zero Coupon (URL) and
where can I buy it (Or can I buy it if not who can buy it?).

From www.treasurydirect.com:

STRIPS
Also known as zero-coupon securities, STRIPS are Treasury securities
that don?t make periodic interest payments. Market participants create
STRIPS by separating the interest and principal parts of a Treasury
note or bond. STRIPS can only be bought and sold through a financial
institution, broker, or dealer and held in the commercial book-entry
system. For more information, contact your broker or dealer.