I do london OL and need advice please

[nalinpr]

I do London OL in Commerce and my Sister does in Science. We both study Cambridge syllabus in school.

So I want to know if we can select Edexcel exam instead and if there a difference between Cambridge and Edexcel syllabus. (I mean study cambridge and sit for Edexcel)

Is there a differnce for exam fees and time period for registration for these two exams

Since we are planning to migrate US after OLs whis exam is better for us.

Thanks in advance