You can get plug adapters in Thailand for not much more than a dollar. Many outlets take bladed plugs and Thai pin plugs. Make sure your electric or electronic devices will accept 220 volts because you will screw up anything only 110 v.
http://www.thailandguru.com/electricity-220volts-thailand.html
Most of the things you can buy back home you find in Thailand. But some things will cost more if they are imported. You are limited to what you can bring on the plane. I bring dumb things like my favorite candy, cheese, favorite peanut butter (available in Thailand but at higher price) and for me extra shoes. I have big feet and size 12 and higher are hard to find and usually expensive. I find laptops cheaper in the US than Thailand. Maybe the same for Canada if your prices are similar to the US.
Remember to notify your bank that you will be overseas. If not your withdrawals from Thai ATM's could be denied. Don't rely on a single debit card for cash. Cards get lost, stolen or damaged.
Two expat forums you can use for long term stay advice are Thai Visa Forum and the Teak Door Forum. They have various categories on living in Thailand.
http://www.thaivisa.com/forum/
http://teakdoor.com/forum.php
Good luck.