i have used plenty of 90 degree cables but never really noted one being thinner than another. not sure that is a thing. plenty labeled "low profile" but i think that is more of the fact the right angle let's it fit where a nominal cable does not.
as you noted i don't see any that look obviously thinner than any other. have you tried one of them yet to know it does not fit?
2 of the ports look like they'd be under the gpu, but the other 4 look like the should be easy enough to get to with a right angle.
also note there is such a thing as right hand and left handed cables. look at the pics before you buy to be sure it fits in the right direction you want it to, whether that is toward the bottom of the mobo or toward the top. most likely the bottom is where you want the cable to point.
i found this out the hard way a long time ago when i got the wrong type.