That particular model uses "green gas". You can substitute propane easily if he purchases the little oiler tip filler combination https://www.amazon.com/Airsoft-Innovations-GunGas-propane-Adaptor/dp/B005WK4D9W
KJW does some of the best replicas at affordable prices. It is a Chinese company. The Japanese do very high end replicas...but will cost hundred more.
That KJW model shoots steel BBs. I prefer 6mm plastic BBs as ricochets are less of a problem.
That model can be purchased from RedWolf Airsoft in China. Cost is about $117 to your door. Be sure to get extra magazines and you will want a speed loader if they make one cuz loading up 26 BBS by hand is hard.