You have a couple of options, depending on how big you want your Gearing to be...
BWN is no longer in business, but you can still find his kits around. His molds have been bought by Yankee Modelworks and will be back in production soon...they produce a 1/350 kit. If you REALLY can't find one, let me know and I have one I may be willing to part with.
There's a company called BaD ship models (Bill and Doug or something like that) that makes a WW2 version and a Fram I Gearing in 1/96 scale...here's the Maryland Silver website that carries their line:
http://www.marylandsilver.com/badship.htm
This is a big model 49" and is not a beginner project.
As for plans and details, let me recommend my book, Fletcher, Gearing and Sumner Class Destroyers in WW2 from the Warship Perspectives line...available just about everywhere. For plans, you can contact the Floating Drydock, Tom carries all sorts of plans for Gearings in their various configurations.
Let me know if you need any further help.
Regards,
Jeff Herne
Modelwarships.com