I tried to run it on a dual core 8 GHz with a HD6770 and it works OK but I think there are background calculations going on thus the need for a quad core PC. I have 8 GB of RAM but the client is 32 bit so you can run it in 2 GB of memory, which is a blessing and an issue. The rest of the memory can be used as a RAM drive, so you can run Elite Dangerous without waiting for the HDD, unless you are using a SSD.
I'm still using my Logitech Extreme 3D, with voice commands, and it is simply awesome. Voice Attack and the game packs are super cheap and they also work for Star Citizen. I was one of the original backers for Star Citizen so I have a long wait before anything is fully working. I hear that they have updated the SC client (another 2.8 GB download completed) but there are no optimisations, so unless your have a i7 with 2 R90s, you will have to crawl.
I'm also looking to do what this guy has done, but with two projectors but that cockpit is mighty tempting to build, even with some half inch MDF.....