The Super Rares in GNW Treasure are Kurama Mode Naruto and Madara Konoha s Founder. Personally i would wait til i get the SR, if its KM Naruto i would go for 5K Madara since KMN is a decent main damage and if its Madara KF id go for Sosp but its up to you now.

I bought 5K Madara when he first appeared and i can say that he worked great for me, he is a nice support that works well with many main damage ninjas. Nowadays pretty much everyone uses buffs and barriers so his mystery is a god bless.

As for Sosp, well, OP kit that CAN be countered as every ninja in this game. I currently use him, he is a strong pos 1 ninja that helps at any amount of power.

Hope this helps you to make the best choice xD