The cheapest graphics card you can play it on is an NVIDIA GeForce GTX 570. CIBOS system requirements state that you will need at least 4 GB of RAM. An Intel Core i5-650 CPU is required at a minimum to run CIBOS. You will need at least 2 GB of free disk space to install CIBOS.
CIBOS will run on PC system with Windows 7 and upwards. Additionally it has a Mac version.