Newb question.

I been researching PBR a while now. and get the idea of basic lighting on the assets when made is the way the game industry is heading. Outside lighting is the old way. Like a colome when completed is practically baked on the assets now and the lighting of the whatever engine doesn’t effect the asset too much. The dialogue in read about the PBR is fascinating. It is like I am going back to my classes in NLP to relearn visual acuity. But my question is what is the best format when exporting? tga,png etc. I am having issues with UV appling to the exported FBX into Unreal. But read it is better to add the nodes and blueprints necessary to finish the material in the UE4. Just need to know what is best export type fo best resolution