The 70m is not simple.
I wouldnt recommend any LED emitter to achieve that range, but it is acheivable with the right camera / emitter combo etc
Id recommend the secware pro IR domes for the shorter range views.
http://www.securitywarehouse.co.uk/catalog/index.php?main_page=advanced_search_result&search_in_description=1&keyword=secware+pro+520