Both are just as difficult or just as easy. I am a native Cantonese speaker so Cantonese is easy for me and Mandarin difficult. Contonese is a dialect commonly used in Hong Kong, the southern part of China and the Hong Kong communities in North American particularly in Vancouver and Toronto, Canada. There are no tools to assist you to learn Cantonese. Whereas for Mandarin there is pinyin. For you, I think Mandarin is easier and more useful to you. With no disrespect to Cantonese (as I am one), I think it is a waste of your time to learn Cantonese. With Mandarin you can communicate with over 90% of the Chinese. Further, like myself, majority of the young Cantonese can apeak Mandarin. So unless you wish to communicate with a diminshing population of "Cantonese only" speaking persons, otherwise, no matter how hard it is you should stick to Mandarin.