The best YouTube camera and lens combination is possibly the Sony a6500 and the Sigma Art 18-35mm f1.8. The improved overheating performance of the Sony a6500 make it a big contender compared to similar competition like the Panasonic GH4. Plus, an edge that the Sony a6500 has over the Panasonic Gh4, is the IBIS (in body image stabilization).
The newest feature on the Sony a6500 is the added IBIS feature as well as the improve overheating performance. However, in this video, I test the Sony a6500 IBIS with several lenses to show you how good it actually performs. With the Sony a6500, I use the Canon 70-200 F4 NON IS to see how well it does at both 70mm and 200mm.