Don't rush,
A too cheap camera could be frustrating, the camera you need will have to have a strong front standard and have a smooth rear focusing standard
So, given your pix, I suggest a Sinar F or P 10x8" back and bellows, that way you won't have to buy the whole kit - If this is too expensive at the moment wait, you still have 5x4"
Also, staying with Sinar means you can get a Sinar-Copal Shutter to improve exposure consistency at wide apertures, where your object of optical grandure will best display itself