Forks are generally not bolt-on interchangeable between bikes, especially when you are going across mfgs. There's the basic fitment differences (spacing, diameter, offset, length, axle diameter/clamping, caliper attachment points, etc.), and there are the issues of travel, damping, spring rates, etc. Swaps are certainly done (most often when developing a custom bike of some sort), but usually there is custom development and machining of hard parts such as new triple trees, axles, spacers, etc. Occasionally a swap will be relatively easy and develop a following (putting CBR600 forks on VFRs comes immediately to mind), but I haven't heard of much interchange for the S10 and doing it just to have a wider selection of used parts would be unlikely to be cost effective. And I've never heard of being able to use the uppers of one fork with the lowers of another. There's a lot more to these things than just a couple of tubes that slide inside one another.
This is all just general hand-waving..... perhaps there is something out there which is a relatively easy swap although I doubt it.
- Mark