Yes an O2-A (or Cessna O2-A will give you better hits) is a two engine military version of the popular C-337 with some significant differences.
Thicker wing skins, about twice as many rivets, heavier weight, hard points for the weapon pods, self sealing tanks, racks of radios and lots of funny antennas on the top.
Used ones sell anywhere for 45k for ones that need some serious up to about 100k for mint ones with low time engines.
Only problem is that you have to have lots of twin engine retractable gear time to get insurance as an owner. I am trying to work a deal with a guy that includes about 200 hours of duel instruction which is what it would take to get good insurance rates. I probably will end up with a C-172 but if the planets all align and my karma is good who knows.