
Hi Mike.
The Corelli 370 series are tungsten wound. (however the G is also nickel wound I think, and maybe even the D. Please contact them if you're interested by Corellis)
Other brands with nickel outer wrap:
D'Addario Helicores
Pirastro Permanents
Super-Sensitive Supremes
Super-Sensitive Sensicores
Super-Sensitive Red Labels
(their Pinnacle and Stellar brands are chrome alloy wound)
Those came to mind. Maybe there are others.
Do you only have a concern if it's the outer wrap?
What about nickel inside the string, under a chromesteel wrap for example?