Hello,
The single rank stick feature will always be true with any cpu memory controller used to drive any memory.
It mean that in any case, single ranked memory modules will always be less stressful for any cpu memory controller than dual ranked modules.
That said memory controller can be tuned in a way to alleviate the stress, even when using double ranked memory modules.
Ryzen 1st gen memory controller indeed fall a bit short when using dual ranked kit under high memory clocks.
Ryzen 2nd gen memory controller have been greatly updated and suffer less when using dual ranked kit under high memory clocks.
Bottom line you can go with 2x16GB dual ranked with your 2700x and achieve up to 3200mhz i suppose, but i wouldn't bet clocking higher.
The other choice is to go 4x8GB single ranked, you should also be able to get up to 3200Mhz i suppose, not so much higher either.
Do not: use more than 2 stick that are dual ranked, never 4 stick dual ranked, if wanted decent memory speeds.
If you want max memory speed always go for 2xXGB of single ranked module.
You can google hardwareluxx memory list, if i post the link i will have to wait the post moderation, it's a great repository of memory modules specs.
I would advice to get a Gskill kit and also check carefully the others bench to leverage which latest kit would fit the best!
Tho the old Samsung IC density is 8GB single 16GB dual ranked module, with the new high density IC Samsung released, i would have expected 16GB single ranked and 32GB dual ranked modules!
Tho I did not found any 16GB kit single ranked, maybe i did not looked at in depth around.