A few years back, jeez... 2/3 years ago I purchased a couple of Cors coils for my 5 pin Tesoro. At that time, they were on sale on Amazon.... but I haven't checked around lately (after Tesoro's untimley demise.) I'd imagine that the stock Tesoro ones are going to be hard to find, of course.
The Cors coils I have are DD, I don't think Cors/ NEL made a concentric version for the 5 pin Epsilon.
I have the stock 8" Donut on my Bandido II Umax, and a smaller (maybe a 6.5") concentric from Tesroro, plus the aftermarket units. I think that the OEM coils are superior, but the Cors DD's still have thier place until the old Bandido gives up the ghost on me.
Best of luck on your search coil search.