I use the Spigen Neo Hybrid case on my P2. I was a bit concerned that it would add bulk, but I dont notice any significant bulk added. I plan on keeping this phone 2-3 years atleast, and this case will help make that happen. Plus, it has a premium look to the back of it.
Looking around, this is the more robust version https://www.amazon.com/dp/B0746Z1KYN/ref=psdc_3081461011_t1_B07471C38C