I think you had better identify your school fast as some exams also consist of non-verbal reasoning
...and the chances are that you will have little or no idea of what types of question will be coming up for either VR or NVR.
My son sat the Bucks 11+ which is NFER, and IPS are very good for that style of VR. The local private school uses a format that is much more like Bond for their entrance exam.
Our experience was that Bond are easier than IPS and other papers, but that's just on a survey of one! Other people have reported the opposite. However, I found Bond to be very different
as much as anything, so I suggest trying the IPS papers to get a contrast.
On the pass mark needed for a scholarship, perhaps it helps if you know that the pass mark for Bucks is 86% or thereabouts, so for a scholarship I would think he would need to score in 90%+. There are quite a lot of children in Bucks who achieve full marks, although the standardisation for age helps many of them to do that.