You can either go with Worst Buy, Target, Walmart, OR wait for Apple's unlocked SIM FREE version. If you want it sooner, get a buddy who's on Verizon to give you their last 4 digits of their SS number and use their account info to buy the phone outright, and BEFORE you turn the phone on, have them call Verizon and explain what happened and that they're keeping their old iPhone.
It's worth it, my Qualcomm 8+ kills my wife's ATT Intel-craptastic 8+ (She's on NEXT while I buy my iPhone outright)
way better reception in rural areas and fast download too. The difference isn't really their if we're in the city though...