Halogen bulbs for 12v converted bikes?

[Micha]

I see that Salis also offers a 12-volt main road light bulb, for converted motorcycles (like mine).
They offer the Philips 12728 C1.
Is a Halogen bulb also possible?
I.e. they do not offer such, but can I know which halogen will suit my headlmp?
I'm not sure that all halogen have a spacial base, I think I once saw a Halogen for std housing?