Honda Restorations is showing one NOS in inventory for US $204.60 plus shipping. Honda Part #31100-354-005. It's the assembly so I believe it includes both the rotor and the stator (the stator part # is 31102-354-005).
http://www.hondarestoration.com/photodetail.asp?hrPart=31100-354-005
I suggest you go to their main website and get the contact details to verify they have it in stock.
BTW, have you checked with your local honda dealer first ? You'd be surprised the parts availability of these old hondas.
Also, not questioning your wrenching ability to diagnose the issue, but how do you know you need a new stator? I've had charging issues with old bikes and often it turns out to be a loose or bad connection in the wiring loom.
I used to own one of these bikes and sold it a few years back. Good luck in your parts search and don't hesitate to ask questions.