Both run flawlessly on PPSSPP and offer similar arena combat.

Covers the Shippuden storyline from the Kazekage Rescue Mission through the battle against Pain. How the "PPSSPP Version" Works

That said, the reality is that most users searching for "Naruto Shippuden Ultimate Ninja Storm 2 PPSSPP zip file download" are looking for abandonware – games no longer sold in retail stores. Use your own discretion, but always scan downloaded files with antivirus software.