Ask the organizers what to bring, and bring twice as much.
I have 100' of hose and about 450' of power cables, half of it 10 gauge.
I think your five pound
extinguisher is too small. I used to have one, and got through a lot of inspections with it, but you will hit the odd contest where it won't pass muster. I would go to at least a 10. Also, if it is more than 5 years old, replace it. Many states require them to be tested and certified when more than 5 years old. Contests that have the fire deparment as sponsors or participants seem to be willing to let the teams slide by a little easier. 
