One more post. This for the 44/60 idea.
I've got everything pretty well narrowed down and collecting a few parts here and there. I've had a 78 Ferd axle with the cast mounts for a while now. They use the 3.125" tubes which is pretty close to the 60 (ball joint and king pin from what I've measured.
Option 1 using king pin knuckles:
Width is a major issue. I measured 10.5" from where the inner C's weld is to the mounting surface for the wheel on my 44. The king pin 60's are 13.5". Since the 60 inner C's are almost 2" thick at the tube I don't see a problem milling off around 1" on the inside side (Kazman tip

). That gets it down to 2" different. I also figured another 1"-1.5" could get had by raising the coil mounts a couple of inches up off the top of the tube. On my current setup my coils bow out to the axle mounts about 3/4" so by raising a few inches the mounts could be moved inward on the bridge and the 60 inner C slopes pretty quickly which would allow it to tuck under the mount some. Hopefully this would keep the width down around 62 or 63 inches.
Option 2 using the Super Duty Knuckles:
The super poopy stuff is only 11.5" from the weld in the inner C to the wheel mounting surface. This helps with the width issue a bunch. I don't see the unit bearing or ball joints being an issue on a lighter rig with 40's or smaller. Currie claims they will take more though. The stock bearing (pre 2005) has to be bored to run 35 spline stubs. Warn hubs or regular drive flanges will still work. If you use hubs a step has to be cut while boring for accomodate a needle bearing for the stub.
The high steer setup is a little more tricky though. The knuckle has to be milled flat and the three studs end up fairly close together. Most are running a spacer tieing the new upper arm to the factory lower for added strength and I haven't heard of any problems even with hydo assist.
All of the Dana 50/60 knuckles are the same except for the F-450 which runs a lot larger rotor and caliper bracket (cast into the knuckle on all). Currie and other aftermarket caliper brackets for willwoods only work on the F-450 knuckle. So if you use the 250 or 350 knuckle you either have to run the stock brakes with 16" or larger wheels or come up with your own mount. Since these have a bastard wheel patern it would be best to drill out the hub and rotor to another pattern.
I like the super poopy option. The WMS to the end of the hub is aroudn 1.5" shorter than a 44 and a bunch shorter than a 60. Also the tighter design in general makes it easier to keep the width down. Problem is cost of parts. The unit bearings new are around $300 by themselves. Best case would be finding a whole housing that is in good enough condition for a resonable price, this has come up pretty short on my end. On the one bend D50 housing I found the yard would only part it out to the tune $700-$1000 (I got tired of listening). Complete axles are running higher than the king pin stuff I've found.
When putting the 1.5" shafts into a front 44 housing I haven't found a factory style seal that will work. The bore from the inside of the housing is too tight to make larger so a normal flat faced seal would have to be used. I didn't see this as much of an issue since I wouldn't plan on changing them often. The OD on a standard 44 is 2.625" so finding a seal that would work on a 60 shaft shouldn't be a problem.