Why do some suppliers insist that you have a dana 44 rear axle to sell you the kit. is it simply due to the rear axle armor or what?  

I'm just guessing, but I think that AEV is not supplying the D35 slider anymore, only the D44. They don't list it for sale with their other skids. Part of the suspension uses the skid in the rear.

Also, why would you want a longarm and a D35. Doesn't make sense. The 4.5" long arm is for 35's, way over a D35 capacity??  

yep, the slider is also my guess on that cause it's what the stinger bolts on to.  

I had a d35 but deystroyed it, im looking at several different options for an axle. I dont like the alum 44. To replace the 35 all salvage yards want between 900 and 1100 for one.   I cant find one locally. I can pick up an 8.8 for close to 200.  Seems like the thing to do. Im actually looking at the RE 5.5. If I go with the re I dont think I could use the rear trilink. Im on the fence between the two of them. It would be down the road. Priority would be to get my jeep from front wheel drive to 4 wheel again.  

LOL...................