Sherwin-Williams used to carry it, but I believe they dropped it because it was in competition with some of their own products (which, IMHO don't work as well). I get it from a Benjamin Moore dealer in Bethel, CT (probably not an option for you)(Bethel, CT, that is) What your looking for is XIM Flash Bond. Comes in white and clear ( I believe that both can be tinted).
The stuff is manufactured by XIM Products, Inc. 1169 Bassett Road, Westlake, OH 44145. 800-262-8469
XIM is no more difficult to use than KILZ and it's adhesive properties will blow your mind. Painting over varnished or urethaned wood used to lead to chipped paint that had to be touched up constantly. With XIM, that won't happen anymore.
When using XIM over varnish or formica or any other non-porous surface, allow it to dry overnight, regardless of what the can says.