My best advice is to try out more than one keyword / phrases start with a small testing budget , test different ads , after you find out what converts stick to it.
I'd recommend, first short list the keywords with their CPC and sent them to your client and ask him for 10% of your total budget.
Its your website business requirement and analyze the competitor of ur websites and track the budget of ur competitor and decide the keywords and then after daily budget.
It's all depending on your keywords. - Fist of all Full R&D on PPC campaign - Select only business generated keywords - Avoid Information keywords - Make keyword in phrase match instead of exact match You may also consult service from reputed company who provide PPC service