[dsraven]

are you looking for an axle that is the correct width srom the get-go or are you open to shortening one side? I ask because the ford 8.8 that comes in an explorer is a pretty stout unit, is available with posi and big axles, disc brakes etc. and the centre section is offset to one side a little. what some fellas have done is to shorten the long side so they can use two short side axles. yes, the bolt pattern is 5 stud but that can be re-drilled or possibly you will be doing some front suspension work and will be swapping to a 5 stud front wheel so the ford axle flanges could be drilled to match the front. I have done the redrill thing to fit a chevy pattern, like the S10 uses, and it was easy. I used an old disc brake rotor from an explorer, marked and drilled 1/8" holes between the ford pattern holes, then mounted it up to the ford axle, using the ford wheel studs to keep things lined up well, then drilled through the 1/8" holes to mark the axle flange. removed the template and did the same for the other axle, then simply drilled those spots for the correct size wheel stud. the rest is self explanatory and you will need to drill the new brake rotors as well.
the 8.8 has a write up on "the ranger station" as far as what came from where and updates, mods etc. there is also lots of aftermarket support for high performance stuff, like c clip eliminators etc. they are about the same in comparison to the chevy 12 bolt but less money and easier to find. narrowing is relatively straight forward ad lots of guys have done this in their home garage.
otherwise I would look at the S10 axles, there are a few widths available with the ZR2 sport truck being the widest. lots of guys put an S10 frame under their AD trucks so the S10 is likely pretty close to the right width but, again, only a 5 stud axle.
personally I would try to find something from a newer vehicle rather than use something from the same era as your truck came with. if you are upgrading the rear axle to be an open suspension then remember the original torque tube rear suspension mounted the axle on a hinge, basically, so there is a axle centreline issue if you simply bolt a different, open style, axle up to the same spring centre bolt. thats a whole different conversation but easy enough to get around.
if thinking of an S10 axle joedoh would be the go-to for info on what width works the best because he does the S10 frame swaps a lot and sells the frame brackets to mount the old body on the newer frame.
post up some pics of your truck and what you plan to make it look like when you're done. will it be a daily driver, trailer quen, stock except for the rear axle?