Picking a new ADC

I'm looking to expand my ADC roster, but I'm completely stumped on who to pick. Right now I only have and . Siv is my main and the only ADC I play with regularity. I have a level 4 mastery on Jinx and Trist, but I'm just not as fond of them. I joke that Jinx and I don't get along well. I've tried all the other ADCs at least once, but I'm really having trouble deciding on who to get.

I think it's mostly that I've become so used to Sivir, and her kit that everyone I try now just feels so wrong and I feel like I'm betraying my main I also just don't know which way to go as far as ADCs go.