Replacing the chip is pretty easy. You can find any number of how-tos on the internet with google. Depending on the placement and size of your case, you might have to remove the motherboard to be able to remove the heat sink (I have to even in my giant Lian-Li case). That's the most arduous process. Otherwise it's just removing the heat sink, removing the old chip, putting the thermal paste on the new chip, putting it in the board, and reattaching the heat sink. For AMD chips the heat sink has a notch that has to face the raised side of the CPU socket.
Once you get everything reassembled, the mobo will automatically adjust itself to the new CPU (I have the same board).
For a video card upgrade... Depends on your price range and brand loyalty. Give us some numbers and I'm sure any number of us will give you an opinion.
Also, that CPU at Monarch looks like it's an OEM, ie no new heat sink. You might think about investing in a heavy duty one for the new chip. The Thermaltake Silent Boost (while being somewhat expensive) has been getting rave reviews from all of my friends.
I might try Newegg.com and go for a retail boxed CPU with it's own heat sink. I think they're only $92 or something like that. Free shipping. Just a thought. Good luck.