Full current H1 Spotlight assemblies can be found here:
http://www.unityusa.com/250-Series-5-Halogen-Spotlights_c_135.html
And the vintage style H1 spotlights can be found here:
http://www.unityusa.com/5-Vintage-Spotlights_c_133.html
The correct spotlight to use will depend on the make model and year of the vehicle the light is being mounted on. Correct parts can be searched for here:
http://search.unityusa.com/application.php
H1 is listed as "5 in Halogen Spotlight"