If we appeal and our appeal is unsuccessful will that affect our position on the waiting list?
No, the two things are entirely separate.
Secondly we live about 10 miles away from the school so we are not in the catchment area of the school. I have also been informed that the school is having two waiting lists one for the catchment students and the other for non catchment students. How can a school have such waiting lists when its a non catchment school?
Informed by whom? If true, I don't see how it could be lawful -
Each admission authority must maintain a waiting list for at least one term in the academic year of admission, for every oversubscribed school, and it must include the fact it will do this in their school’s published admission arrangements, making clear that children will be ranked in the same order as the published oversubscription criteria.
I was also wondering what documents do I need to submit for an over-subscription appeal?
It depends on what arguments you are putting forward. For example, if part of your case were to be that he excels at maths, and that this is one of the school's strengths, then you would need as much evidence as possible of his ability in this area.
Examples of reasons commonly given at an oversubscription appeal can be found in the Q&As.
Do I need proof of ds's academic abilities?
Normally for an oversubscription appeal, you don't need to prove overall academic ability. However, if score was the criterion for entry, and he qualified but was expected to score even more highly than he did
, then you might wish to include evidence to back this up.