Click: Longview Custom Towing Mirrors for Ford Ranger 2000 - CTM2200A
They're not extendable and extendable ones like found on the 3/4 or 1 ton trucks just aren't available/aren't made for Rangers....OE or aftermarket don't exist.
An option many go for is upgrading to 2006+ mirrors as the glass is considerably larger and the glass is actually set farther outward. It may fit your needs.
I added large blind spot mirrors to mine. Coming from driving tow trucks for a few years now, I absolutely love the big blind spots....you can see everything. I have little issue towing a 6'x10' enclosed trailer with my Ranger and these mirrors.