I've tried all of the above on my Kamaka soprano and none of them are high tension enough for my preference. I use Aquila concert strings on my soprano.
Yeah, I remember the guys at Aquila saying a couple of years ago, that concert set on soprano works if you want higher tension. I will try that. Thanks!
Try D'addario Pro-Arte strings for Concert uke. They are hard tension strings, and are the strings Jake Shimabukuro uses.
I'm sure they'd work on Soprano.
I have some coming in which I plan to put on my Mainland Gecko soprano.