Wheel looks good. As for rims both 15x6.5 and 15x7 will work with 205/50/15 rims. Just a matter of preference really. I went 15x6.5 cuz they're a bit lighter but im running 195's anyway. 205's on a 15x6.5 will have a kinda bulgy look. Doesn't really look weird I kinda like it, but like I said it's preference.
Of course with how low you are 205's may rub...