Help needed urgently!?

Can someone please advise me on which martial art i should take up,i have done a bit of taekwondo and karate but long finished,its just now i stopped playing rugby i fancy doing martial arts.My initial choices are judo or korean kickboxing as there are cles locally.I was also wondering how physical is korean kickboxing and is it any good?Also,if it helps I am 13,5 ft 6,and 60kg.I formerly did the 300m,100m and rugby so i would base choice on martial arts suited with these attributes in mind.Or shouldent i bother at all?SOmeone guide me please!