With the Detroit in the front I twisted up both my front axle splines pretty well. I switched to an ARB up front and Calmini heavy duty axle shafts, but still run stock birfields. I finally blew one up, but it took a whlie of beating on it pretty well. The ability to leave the front end unlocked takes a lot of the load off of the birfields when driving around and allows me to unlock it when backing up, the true killer of front birfs and CV shafts. I do have a set of the Trail Tough Chromo axles, just haven't installed them yet.
For the rear I am running stock Sammy shafts with a spool. I finally broke a rear axle, about 5 minutes after breaking the front axle, and on the other side the spline was pretty twisted. With a locker or ARB in the back you probably won't see nearly as much damage, as just driving around puts extra wear and tear on the rear axle shafts with the spool. I'll pull them this winter to see how they are holding up with the new rear end before looking at replacing them with stronger units.
Once all is said and done though, if I was starting from scratch and wanted to build an SJ-410 on 33-35" tires I would probably go with Toyota to start with unless I had the Samurai parts laying around to swap to. Since you need to swap axles anyway.