I need help deciding between imperial fists and raven guard for 40k

I'm in a predicament because I'm buying the starter set soon for my second and third army (first being thousand sons) and I like the colors of the imperial fists but I really like raven guards wraith slip stratagem and some detachments (just not color scheme) as well including named characters from each chapter (tor garadon, kayvaan shrike) if any one can help me decide with the pros and cons of each please let me know