Goldberg Tiger 60 any of the Sig 4 stars, Sig Astro Hog and Although not a Kit but I bet the Sig Rascal 40 would make a great second plane as well. The Tiger and the Hog can be built with trike gear if you don't want to step up to a tail dragger. You won't find a plane that flies better than the Hog but the parts are not laser cutter and the would be a bit more work than with the other kits. INMO the Sig SE although a good kit to build (and fly) is probably a bit much for your second airplane. Its large control surfaces and mid wing design just make it less forgiving than most low wing airplanes.