Maybe this is just my case but I only ran 33's and I was replacing something in my front end like every week. I dont want to be a downer I am just telling you about my problems when I did the same.
I had a 2" body lift, the 2" superlift (a biiiig mistake), and the 5" trailmaster
Given I did do A LOT of wheeling, I eventually had to replace almost EVERY single moving part in the ifs besides the differential itself. I ended up replacing the ball joints multiple times and the cv joints multiple times too. Also I had to replace the wheel bearings once and by a couple months later after I took them off when I did the solid axle swap they were already bad and ready to be replaced again.
By about 4 months later I couldnt even drive it anymore my camber was so bad and I could not get an alignment until I pretty much replaced everything in my front end..........AGAIN!!!!
That is when I got pissed off at ifs and did a solid axle swap.
I will say that the trailmaster is not designed quite as well as the superlift but maybe you will have a better experience than I did.
Bubaloo whatchu talkn bout SAS looks ghetto?!?!?! is it just b/c I dont have your bling blingedy front skidplate anymore?? ahahahha, j/k but I bet I could OWN you like no other in a flex test.
If you actually plan on offroading go with the SAS
If you plan on it being a show truck and it isn't your daily driver and you dont plan on going offroading go with the IFS lift.
From what I have read of what you wrote I think you should go with the IFS lift, and if you treat it nicely and use quality replacement parts you shouldnt have too many problems
I hope some of that made sense, have a nice day

[size=75][url=http://s80.photobucket.com/albums/j162/coffeedrnkr15/]The Crazyblaze[/url]
d44/d60 5.13's, atlas 3.8
[/size]