There is a nursery curriculum already, it is EYFS. It is well thought through and is our national approach to this vital stage of education. If you take account of the characteristics of effective learning you won't go wrong. It has the benefit of fitting in with all schemes and KS1 initiatives but can stand well on its own, being based on experience and research.
Please ask yourself if this is about what is best for your children, or what is best for KS1 aspirations?
For more information go to https://www.foundationyears.org.uk/