Definitely Speak Samsung Tab S2.
With Android 6 you can insert an SD memory and recognize it as an integral part of the internal memory. When you format, you can select how to use it.
Andoird 4.4 did not allow access to data, except for preinstalled apps by the manufacturer and that have root permissions.
From Android 5+ you can use SD as external memory if you enable the folder to be accessible. From the Android 6+ app instead of allowing each App to access SD memory.
I did not quite understand how you want to access SD memory, so I can not tell you how to answer your question. In any case, you can only have SD access with only version 4.2 or lower.
P.S. After having a Samsun Tab2 and a Tab3, I preferred to buy Huawei Mediapad M3. I think it's more powerful and a good screen (359 ppi density). Some prefer AMOLED for very saturated colors, but has a less defined screen than the previous version (only 264 ppi density)