Using Razer eGPU with 3D part laptops ?

Hi, I need an advice. I have my Asus N76VJ laptop with this specs : Processor Intel® Core i7 3630QM Windows 8 Chipset Intel® HM76 Chipset Memory DDR3 1600(0.C.) MHz SDRAM, 16 GB Display 17.3" 16:9 HD+ (1600x900)/Wide View Angle LED Backlight Graphic NVIDIA® GeForce® GT 635M with 2GB DDR3 VRAM Storage 2TB HDD + 500gb SSD Storage 2TB HDD + 500gb SSD It is any affordable option to make it a machine for 3D editing & 4K video editing. I hope you will help me a lot with advice what do I need exactly (models) to install or buy. (Like external eGPU for example) My budget is around 500$ +/-