There's a thread in the Tech/Geek Zone here mate http://www.owlstalk.co.uk/forums/index.php/topic/234256-genesis-kodi-users/
Off the top of my head the following are pretty good.
Sportsdevil
NJM Soccer
Operation Robocop
Moneysports
UK Turk Playlists
This site will also run you through how to install each one https://seo-michael.co.uk/tutorial-how-to-install-njm-soccer-kodi-xbmc/
You may also need to download ADBFire to 'push' some of the files to the FireTV as well - you can get that here (as well as the guide to install) http://www.htpcbeginner.com/setup-fire-tv-on-adbfire/
WatfordOwl's post in Just got Kodi on my FireTV was marked as the answer