You can check my web site www.benayahblum.co.il or my company's website www.ahalan.co.il . I have a few programs of different character of tours there. Once you decide what tour you want to make, I will be able to plan for you YOUR specialized tour, and accordingly give you advice as to what to wear, eat, etc...
At any case, in January you should take some protection against the rain (it might even snow in certain areas in Israel!).
Benayah Blum, Chief-guide & Product Manager
Ahalan Olympus Ltd.