You only need to do three but if your school makes you sit 4 then I guess you have to do 4. Any combo of the above subjects would be good, they are all well respected. Further maths is very hard , unless you are brilliant at maths. It is good to have an essay subject , which you have. Choose whichever you like the most and think you will do best in.
Not having English A level will not hinder your application to law at Oxbridge or London.