The best combination to cover all top economics courses is probably: Maths, Further Maths, History, Economics
If you couldn't take the above 4, A2 Combinations would be:
Most mathematical courses = Cambridge and LSE: Maths, FM and Econ
Slightly less mathematical = UCL and Warwick: Maths, FM and Econ probably best but FM/Econ could be replaced with History or physics
Oxford is much less mathematical and most take: Maths, Economics, History
Your options look fine tho