Supply Units (White Giant)

Where can I get jeeps and not heavy jeeps?
Where can I get tanks and not heavy tanks?
where can I get anything with "aa" in the weapon name?
When a corporation is made, do the things it produces go on the world market? OR does the country it is in can only use it.

Jeeps, tanks and aa weapons, under defensive weapons.

All corps products are offered on the world market, unless you contract them youself.

and how do u contract them youself