I'm currently looking at buying a vRS but noticed it has a couple of issues: all door seals need doing and it needs new lower arms as front lower suspension arm pin or bush is worn along with nearside + offside front suspension arm pin/bush

does anyone know what this is likely to cost to have done through a Skoda independent?

Are you sure that it's not the console bushes which have gone? Because replacing the lower arms won't fix that issue.