Even if you no longer want to participate pvp events it's still worth it to get Konan. She is not just great in pvp but also in other stuffs like Ninja Exam/Group Exam/TI where you can help other members and have fun.

Sakura on the other hand is great for pvp and for collection purpose but other than that, she don't help much in other activities.

But it's up to you tho, if you already done all exam then go for both Sakura and Yamato cuz you get more ninjas for collection that way. Otherwise I think Konan is better choice for pve than sakura.