The Revell kit will probably be better in quality than the Amati kit. I recently converted the Amati kit into a late war Type VIIC. It was a bear to build, taking more than 400 hours, most of that was involved with blending the metal hull sides into the resin lower hull with wooden bulkheads underneath...the PE deck is in seven parts, and it's heavy brass...
Goto www.modelwarships.com and click on Feature Articles, it's all there for you to review...I'll never build another Amati U-boat again, and I'm partial to U-boats.
Jeff Herne
Modelwarships.com