i bought a roll of puck board off the internet for like $40 from http://www.backyardrink.com
this guy is good and has many different option (sheets, rolls etc.) i just layed 3 strips side by side (off my roll) for my 18 inch wide box. it seems to work well. you pay more but it slides like a charm
just my ideas
I remember doing all those tricks, then I woke up...