Hi,
Have you done (or thought about doing) any testing and looking at stats to see which would work best for you?
Personally, I would be quite wary of just changing to a new form structure without doing a level of A-B testing first of all. You want to know for sure, which is going to work best for you.
I understand the points about drop-off but those that don't, you get a higher level of enquiry, but can you do better than this? Is 1 question per page too little? Could you get away with 2 and halve the process? How about 3? How about just 2 pages, one for personal and one for requirements?
There is a lot to think about here but please don't try to make the decision yourself as this isn't necessarily what other people want.
Head over to Hotjar (or something similar) that will allow you to watch how people actually interact with your forms. Setup goals in Analytics so that you can see where people are dropping out. Tie all of this in together and use real visitor numbers to help you with your decisions.
I hope this helps a little.
-Andy