HD TO SWOP FOR NVIDIA IN PRETORIA

I have a HD specs At A Glance Manufacturer:AMD Series:Radeon HD 5k GPU:RV850 Release Date: Interface:PCI-E 2.0 x16 Core Clock:850 MHz Shader Clock:850 MHz Memory Clock: MHz ( DDR) Memory Bandwidth:76.8 GB/sec FLOPS: GFLOPS Pixel Fill Rate: MPixels/sec Texture Fill Rate: MTexels/sec Details Max Power Draw:108 W Noise Level:Moderate Framebuffer: MB Memory Type:GDDR5 Memory Bus Type:64x bit) DirectX Compliance:11.0 OpenGL Compliance:3.2 PS/VS Version: Process:40 nm Shader Processors:800 Pipeline Layout:VLIW5 Texture Units:40 To swop for a Nvidia 560ti ot 570ti or more or less same spec card