You will want to look for a good three season jacket. Something with a cold weather liner and vents for warmer weather.
Then set your sights on a summer jacket made of mesh.
It really depends on your budget.
I was a 2XL guy and I found my choices a bit limited.
Cycle world Superstore had some decent larger riding gear, but quite a lot of it is last year's stock etc.
For rain gear, wait until you have a jacket that fits then purchase a set of that yellow two piece that you see in construction supply stores.
Order off of the Internet only when you know it will fit, by having previously tried it on in the store. And they will hit you with duty on clothing purchased and shipped across the border.
Gpbikes has some larger sizes, but you will probably have more luck with Royal Distributing just down the street.
In January there is a very large motorcycle show at the International Centre that will have all the vendors in one place and much much more to choose from. Save your Xmas money for this one.