how many peas to a pot?

i need to put out some peas but my growing trough is not ready yet (needs painted and lined if it ever stops raining) so i will need to put them into some 42 litre trugs.
how many could i put in?
ive not grown peas before so was going to make  wigwam style support with bamboo canes, would this be suitable?

the peas are jumbo.

In my experience peas won't climb up canes/wigwam by themselves, you will need to keep tying them in or put some netting round

Thin twine wound round the canes at intervals works well for a friend of mine, and avoids the possibility of not being able to pick any peas which grow inside the wigwam. 

You may have to consider some extra support for the wigwam if you grow tall varieties unless it is in a very sheltered spot.