I have had my serger E winder for several years and I got it at Nancy Notions and have seen it several other places. It works great unless you used different machines to wind as each machine takes a different rewinder bottom. The spools are special spools that you wind onto. I have seen then at some Hancock's stores also.
Serger thread is only 2 ply and sewing machine thread is 3 ply. That is why serger thread is thinner and not as strong.