Oh the joy of swapping the front diff lol.. Very rewarding though, especially cus of the ARB locker. Get ready to invest in some (more) spare CV axles.
BTW, word of advice... I don't always trust the parking/emergency brake to do it's job when I have the front end on jacks. Especially now since I don't have one at all haha. Be sure to throw something in front and behind a rear tire to "chalk" it from the truck rolling on you!
Yeah I thought about the axle problem but I was willing to move forward. I do have spare axles and I am going to do a manual hub swap so I am thinking if one does break with the manual hubs I wont have to stop right where I am at to fix. And now that I have done axles a couple times they really aren't too bad to do anymore.. still not fun but not scary.
Good idea about the rear wheels. I used to never worry about crawling under vehicles but as I get older I worry more about that sort of thing :/
I'll throw in my $0.02 here (or maybe $0.01, LOL). I'm new on this site, but been doing the IFS thing for 15 years now, on two different generation IFS, and while I haven't done super hard rock crawling, I've been successfully (no winch assistance) up several of Colorado's more challenging trails (Blanca Peak, Holy Cross to the city, the Chutes, and so forth). Hopefully below hasn't been covered too much before (hard to wade through the whole forum).
Point 1:
Front lockers will save the axles, provided you remember what you are doing. If you try to turn full lock into a ledge, and give it a bootfull, the axle will break. But if you keep your head in the game and try to keep the axles within their working angles, they will hold up fine (up to 33's, after that, no guarantees).
What I've learned the hard way: you must get factory axles (remanned or new is fine, the main point is they need to be Japanese steel). I have put several parts store "lifetime warranty" axles into my various IFS set ups. All busted or blew apart within a few months. Toyota factory, I only broke with an open front. Lifetime warranty is a joke. Sure, you get a free axle, but the hassle, time and aggravation on the trail is worth buying factory new 10x over.
What usually breaks axles is shock load, which happens with an open front IFS all the time. The usual situation is trying to get through something, a tire is in the air, and then the truck bounces down, bringing the tire to an immediate stop while under power. Also, I'm sure most know, but in case not, with an open diff, when you have a tire in the air (and the other stopped on the ground), that tire is spinning 2x as fast as your ring gear. So the loading is pretty bad.
With a front locker, you can often keep going forward in a slower, controlled fashion, particularly if you also have lower gearing.
Now, I'm in the Colorado mountains, so I have the luxury of slow, non -mud type wheeling. I realize that people in other places where mud is a common thing need to keep momentum up, and they will probably break stuff more often.
I post this as a counter to the 100's of posts I've read over the years about how front lockers break stuff. If you learn the system, you can keep the truck together through some pretty rough stuff (at least the axles and diffs, alignment is another matter).
I'm not saying that you should not get spares, I always have a couple in the truck. But rather that I wouldn't worry about it so much.
Point 2:
Manual hub axles neck down further than the ADD style. A buddy of mine (long since SAS'd) had a manual hub truck, and those things broke constantly. I don't have stress test data or anything other than experience, but seeing his axles vs mine and seeing them break caused me to rethink going manual hub.
You might be fine, but I would at least look into it before you go spending the time to swap it.
Point 3:
LOVE the truck. I'm really wanting to get one of those surf spoilers. Really nice job with it. Also waiting to see how the interior paint turns out. I need to paint a couple pieces and can't find the right color.
Anyway, as always, take this jibber jabber for what its worth, LOL. I'm just some dude on the interwebs with long rambling posts,

Hope its helpful to you!