There are two full kit hydrofoil models.
The first and foremost is the PGH-1 Boeing Tucumcari by "Aurora".
It was also part of a models by mail club offering in the late '60s-early '70s.
The Tucumcari Hydrofoil model can still be found on E-bay and will sell for around $40-$50 dollars
The Second is the Boeing PHM itself. IThere is a resin kit produced by White Ensign Models. http://www.steelnavy.com/wem_pegasus.htm
Of course if you want to get serious, there are these two models.
http://www.rcgroups.com/forums/showthread.php?t=274191&highlight=hydrofoil
See post #123 here
http://www.rcgroups.com/forums/showthread.php?t=41502&page=9&pp=15