Do I need a separate home inspection if I've got a good contractor doing a gut rehab?
You still might want the inspection.  Even though you don't care about the electrical, plumbing, heating, wall and floor finish, you are counting on the underlying structure to be sound.  You might want to know about, for example, evidence of water damage / possible mold, rot in the sill or beams, sagging floors, possible asbestos, evidence of termites or other pests - many things you might not have thought of.  

You may be able to ask the inspector to place less emphasis on the systems you know you plan to replace.