My husband really wants this gun, the Colt Defender, and I would love to surprise him with it. Need some help please!!! 
The Colt Defender is still being produced and can be ordered from Colt by a firearms dealer.
I would stay away from the Agent. We carry both and even though they both sell for about the same price, the Defender seems like a much better quality gun.
Of course, if you're willing to spend 50%, you can get a Kimber.
By the way, a used one is being sold
here.