I bought an atmega 328 pu chip and come to find out it has the uno bootloader preloaded. Anyhow, I need to upload the duemilanove bootloader since that is my board. How do I do this?
You don't. Just use the chip.
The duemilanova with 328p-pu works fine with the uno optiboot bootloader. I have actually burned optiboot onto two 328 duemilanovas I have.
Just remember to select Board = Arduino Uno in the IDE.
I put the Uno bootloader on all my 328P chips. Then select Uno as the board type.
SMD chips have A6 & A7 available as additional analog inputs, but I've not used those in a project yet.