I ordered the Strongback low back chair (this is the blue one they have pictured) that seems to have really good back support (assuming he'd appreciate that being a big guy) and is rated at 300 pounds. I haven't tried it out yet, but it has good reviews.
STRONGBACK Low Gravity Beach Chair with Built-In Lumbar Support, Black and Grey https://www.amazon.com/dp/B01194YRTU/ref=cm_sw_r_cp_api_T278xbX8RESFA