I am purchasing in few day imac iMac i5 with 8GB RAM and want to run 3D software for design work to set up a virtual image. I have thought of using Paralles 5. I just want to know what will be the best version of windows to get of my new machine. I have read on some post difference between 32 bit and 64 bit windows version and I found that 32 bit does not support Ram more than 4GB. I am just worried about the performance issue because there are not 64 bit drivers for all devices. If anyone is having detail information about this then I would like to advise on a specific version of Windows.