A good size for 17" wheels would be around 330mm, any calipers with a radius that suits 265mm(most likely 260mm ?) discs will not be a good idea to use on such a larger radius disc.
There is always the mk3 mondeo discs and calipers 300mm, just redrill the discs to 4 stud, or other options are a s/h set of brembo's and FRS mk1 discs with brackets.
Most but not all are radial mount in the wilwood range.
tabetha