Hello Arishusa!
I do not know what part in the world you are coming from, so manufacturers/suppliers may be closer to you than the ones listed below. I have no information on where to get off-the-shelf 37mm Ti-valves fitting straight in. There are a couple of Ti-valve manufacturers that propably can help you. Perhaps you know them already, but anyway:
Kibblewhite
Xceldyne
Ferrea
Del West
There are more options if you are coming from Oz or Europe.
I have a cutting tool to make the groove for the clips. That is how I can buy "blanks" and fit them to the actual application.