Hmm not sure if thats how I would do it.
First off how would the customer know what he wants? Usually I start of by asking the purpose of the CCTV and then telling the customer what they should have not the other way around. After all Im supposed to be the expert not the customer. I do go to some surveys and customers have an idea of what they want, usually I discover what they want is not what they can afford or has yet to be invented LOL.
Much as I wouldnt want to tell you how to suck eggs you could simplify what you need by asking:
1 Purpose (This tells you what sort of spec they need)
2 Budget (This tells you what sort of spec they can afford) You could include lease purchase in this discussion
3 Is the CCTV going to be constantly monitored or controlled by a guard ect (If the answer to that one is no, there is no point to PTZ cameras)
After you have worked out the above all you need is a spec sheet on a Driod, The customer is not gonna know what type of lense or cable you need to work that one out.