Off the shelf? I could NOT tell you, and I'd advise against just getting a Warmoth (made to a Fender standard neck pocket and length) or similar Fender type replacement.
This is something where I'd honestly say, the neck could be made from scratch by somebody with the skills if you know a luthier. Chances are - somebody out there would be willing to measure a neck pocket and neck, and make a copy for your with a 1 1/2" width like a Fender Jazz or Ibanez Soundgear.
But I can't say finding somebody willing and able would be easy, and I also can't say that it'd be affordable or worth the money. The concept isn't all that difficult to grasp for somebody who knows how to build a neck, it's just very niche thing you're asking for and commercial off-the-shelf solutions aren't likely to be out there, you'll have to look for somebody who can make you a bespoke neck and that probably won't be cheap.