use makehuman
Making Custom Character Models is not that hard. Use MakeHuman, free, with Blender, free, using FBX export, import, export. Unreal Engine 4 easily imports FBX animated MakeHuman characters. I use free BVH files to animate them in Blender. Since MakeHuman can put out any number of morph variations of your male or female characters, you will probably just have to save out each variation, and import them into the Unreal Engine 4. You can take the MakeHuman pipe-line a step further, by importing it into Substance Painter, and then painting in real time PBR textures.