Quite a few from the States have a Tracking Number on my ebay checkout.
Not sure if this applies once it leaves the U.S.A. as none say delivered, even though it has arrived at my address.
International Signed for is a Signature but as far as I'm aware tracked within our shores and then depending on Country all you get is the signature.
If it goes missing ? (Only Tracked in certain Countries)
AIRSURE is the one I have used for Expensive Items. Strange thing is there's No Signature, but does have confirmation of Delivery.
On a normal Item Proof of Posting is the one I use.