Hi Dave_Hazel,
I can only say what we (my OH and I) have experienced, maybe this will be of some help to you and others!!!!
My OH and I are here in Alberta, Canada through the PNP, My OH is a long haul truck driver- The company who hired him conducted their interviews for prospective drivers and their families in the UK. We met the Hiring Company recruiter and the representitive of the Immigration company that the Hiring company use.

The company required my OH to have a minimum of 2 years Class 1 driving experience in the UK and Europe.
I think the amount of driving experience required, differs from province to province and company to company., so you will need to check it out before hand.

Canadian companies advertise in the UK through the national and local newspapers, trucking magazines like Truck and Driver, Trucking etc, so check them out. 8)
One piece of advice though is be very careful of some of the immigration companies, as they prey on peoples desire to come to Canada, which can have a very high cost, as some people here in Canada have already found out!
If you get a job offer through the PNP process, The immigration company who works for the hiring employer,

should sort out your Work permits, LMO, flights, etc it shouldn't cost you anything, as all the expenses is covered by the hiring company!

8) The only thing you should pay for is your spouse and kids (if you have any) to come over. 8)
As for driving in Canada, it's like driving Miss Daisy here, totally different from wacky racers in the UK lol!!!!
Hopefully I've gave you a little more insight...................
Shazza 151