At the Canadian newegg probably either the OEM 3.0 Ghz Phenom II X3 740 BE or the 3.2 Ghz Athlon II X3 450 CPU (Both are very close in benchmarks and price).
One comes with a heatsink and fan, warranty the other is a little cheaper and slightly better although at a slower clock speed.
http://www.newegg.ca/Product/Product.aspx?Item=N82E16819103699
http://www.newegg.ca/Product/Product.aspx?Item=N82E16819103886
About $80 CAD for the Phenom IIX3 + Free Shipping
About $91 CAD for the Athlon II X3 which doesn't have free shipping (It's $10)
As to a motherboard this is a good one although AM2+ it's cheaper and a good choice.
GIGABYTE GA-MA785GM-US2H AM3/AM2+/AM2 AMD 785G HDMI Micro ATX AMD Motherboard
http://www.newegg.ca/Product/Product.aspx?Item=N82E16813128394
About $60 CAD + Free shipping
Here is another similar type slightly more expensive but comes (no kidding) with a router card,a infrared remote and detector.Meant for a HTPC it also works great for a desktop.
http://www.newegg.ca/Product/Product.aspx?Item=N82E16813186180
About $85 plus $13 shipping = $98 CAD
Basically not putting you over the $200 price range I would say the
Phenom II X3 740 @ $80 and the GIGABYTE GA-MA785GM-US2H motherboard @$60 for a combined total of $140 CAD would leave you $60 for DDR2 RAM which you could choose either DDR2-1066 or DDR2-800
http://www.newegg.ca/Product/ProductList.aspx?Submit=ENE&N=100007610%20600006125&IsNodeId=1&name=DDR3%201066%20(PC3%208500)
http://www.newegg.ca/Product/ProductList.aspx?Submit=ENE&N=100007610%20600006107&IsNodeId=1&name=DDR2%20800%20(PC2%206400)
You might be able to get 4 GB RAM.Check the motherboard manufacturers recommendations and qualified vendor testing list on the memory before ordering.
These motherboards are mATX.
By the way I own both motherboards (but am from the USA) and they work great.