The drive shafts came from Six States.
I spoke to Eric since he knows about the defenders very well, including the clearance with the front catalytic converter and the grease fitting. They are balanced units and use the common "Jeep" U-joints. This is good for part supply  on the trail. 

Shipping was a problem because their outside machine shop could not make the adapter flanges in a timely manner so I decided to make my own and not spend the additional $75.00 each for the flange. 
The time for me to draw on Auto Cad and material, machining exceeded $75.00 but it just adds to all the custom made accessories on our D90 :)
We used 4140 steel and machined so the CV bolts would lock into position when mounted. The flange was counter bored so a socket would fit to tighten the nuts.

I started the installation from the rear first.
Since the OEM shaft was removed I removed the large "Philips " screw holding the drum in place and then tapped the brake drum with a rubber mallet.
Inspection revealed the pads are still good. 
I sprayed degreaser (brake clean) to clean the flange.

After mounting the adapter flange ( now panted black to prevent rusting) installation with new 7/16 fine thread bolts to mount the CV.

 The rear was straightforward but I did retighten the pinion nut since it was loose enough I could turn the nut by hand.

I torque the pinion nut to about 110Nm. 

The front CV has plenty of room even with the large adapter flange.

The fit is tight near the catalytic converter. 

The grease fitting is near the yoke so it will not rub the catalytic converter.

After a test drive all of the vibration and shimmy went away. It now drives like a stock D90.