I went with a commercial tour last week; you'll find brochures from
several operators on display at your hotel. I went with Cosmojin
Travel, who seem to use Korean Veteran's Association for the Panmunjom
section. I have another brochure here from Seoul City Tour. As far as
I can see they are all the same--necessarily so at Panmunjom because
at Camp Bonifas you get a briefing and then transfer from your tour
bus to one driven by a ROK soldier. The guide from your company
delivers the briefing and the commentary in the ROK bus.

You get to climb and take photos from a platform overlooking the JSA,
then enter the conference room (photos ok), then go to the Freedom
House where you can look through powerful binoculars (500 won coins
needed, change available) at the North Korean "propaganda village" (you
are *not* allowed to take photos from right up by the binoculars--you
have to stay behind a yellow line about 10 feet back for photos; a
ROK soldier made me delete some photos I took from the wrong side),
then briefly stop by the Bridge of No Return and the site of the
tree incident (you cannot leave the bus but photos ok). A hint:
when inside the conference room, look out the windows--you can see
the actual concrete border line running between the buildings,
and you can see the ROK soldiers standing in that iconic pose half
exposed and half protected by the building.

I think the only difference in the tours is in the quality and fluency
of the guide's commentary (which is hard to predict in advance):
you will get to see the same things. My tour had both English and
Japanese guides and the Japanese one seemed much more informative,
but I wasn't able to keep up.

The DMZ tour is less interesting the the Panmunjom tour but seems
equally predictable: Dora Observatory, Freedom Bridge, Third Tunnel.
The third tunnel is a *hard* slog down and back (in a hard hat, but
constantly banging your head on the low roof) if the train thing is
not running.

You can combine both tours with a switch over (and lunch) at Imjingak.

Prices are typically 50,000 won for DMZ, 80,000 for Panmunjom, and
130,000 for both.