What to Buy in US (Everett WA) Before Crossing into Canada

I bank with a Toronto based bank, but I will check to see what fees might be involved with Canadian debit and credit card transactions.
The Burlington WA Costco seems like a likely place to stop for supplies in the US. Where should I cross into Canada if I want to avoid the Vancouver traffic? And where should I stop over the border in Canada for items like eggs and chicken?