Recommendations: Wireless SIP phones

I am a newbie to Asterisk.

I am about to deploy an Asterisk PBX with Polycom desk phones (430’s and some 550’s).
I have now been asked to include about 10 wireless phones for use in a warehouse environment. They would like the push-to-talk feature if possible.
They have to be durable

What are the most common phones that are the easiest to use?
Any recommendations are appreciated!!