Hmm, don?t go for hires cameras as most importaint thing, you get stuck with RAM wall, but if even then it exist way around it. So in principle, a 550D - 600D is ideal to start, invest in Hiquality objectives afther you get the right "size" that can be used later with PRO cameras Like 5D III or similar......
For the PC some Intel PC, with 8 RAM Slots - 64 GB RAM ( socket 2011), that should be enought for now.....