You're comparing a Dana 35's 7.5" Ring to the Ford 8.8" Ring. The shafts are 1.13" for the Dana 35 and 1.31" for the Ford. Also, look at how the D35's shaft tapers down at the splines. This is where they all break. The C-clips aren't the real problem, it's the pencil shafts. If the shafts were thicker, they wouldn't break and the axle would walk out. C-clips don't add any weakness to the shafts. I've never heard of anyone breaking the C-clip or the groove off the shaft before. But once the shaft breaks, it's a PITA to have to shaft walk out. This takes out the brakes and its a whole bunch of bad.
If I had a TJ and was not looking for tires over 35", I'd really consider the Rubicon D44 swap. The only consideration that should be made is gear choice. If you keep the lockers that the Rubicon comes with you will be limited in your gear choice. The lowest gears for the TJ D44 are 5.13's. This is because the carriers they use are designed for higher gears. Instead of making a gear split they made custom 'thick' gears. If you change the lockers then you should be able to use any D44 gears though.
Shop around for axles, there are many companies out there other then Dynatrac and Currie.
http://www.sunrayengineering.com/http://www.drivetrainspecialists.com/http://www.drivetraindirect.com/http://tricountygear.com/I know there are many more then those...
