I don't know of anyone making a 1/2" needle valve This valve works if you're looking to mount the valve on a surface.
Do not mount this style valve inside an enclosure. A leak could be disastrous!
That's an option but I need to find out if it is rated up to the 30 psi that I am using. I found some 1/2" panel needle valves glut it they are out of stock. If all else fails I'll just use ball valves until I can get the needle valves.