No problem, Home Depot entered the Canadian market 16 years ago. Lowe's is in Ontario. West Systems is available across Canada.
Assembled and flown an Avistar. Liked it so much I have a newer one at home in a box. Used a ST GS40 it balanced perfectly. Great plane. Just follow the instructions with the ARF.
Jim
ORIGINAL: Charlie P.
Should I even build it by myself?
You're in luck. If it's an ARF you don't have to build it. Just assemble it. ;-)
Don't know what you have in Canadia, but places like Lowes, Home Depot or West Marine will sell West Systems or System Three epoxy that is generally much better (and cheaper per ounce purchased) and longer pot life than the 5, 15 and 30 minute Devcon and similar stuff.
30 minute is fine for most R/C uses except laminating fiberglass. Don't sweat the little stuff.
As far as your extra piece: lots of ARFs are now including parts needed for electric motors vs. good and proper engine installations. If it's not mentioned in the manual forget it.