Box Slider Material

Just got my hands on some 6' pontoons so I'm prob. going to make a box using them... just trying to figure out what to use as the surface
if anyone can add to these ideas and/or give me some prices that would be awesome

FPR panels
Kitchen/Bathroom flooring stuff
Trex decking
?
?

Any help would be great thanks

Azek trimboard 4 x 8 sheets, 3/8" thick. about $70 a sheet but worth it. I tried using that bathboard and it started to tear after the first day.

cool beans....will home depot carry this? my mom is re-doing some rooms in the house and if I can sneak on some charges hopefully they'll go un-noticed