You can buy the paste at electronic stores like RadioShack or bestbuy or even walmart or even better yet order it online.
i guess it all depends on your budget. if you buy it online you will most likely spend about $10.
If you buy a retail boxed processor, yes. You do get a heatsink fan (HSF) with the processor.
yes
Yes, Petco sells tooth paste for animals.
You can, there is tomato paste and tooth past and probably others too.
in shop oar mall................
If quiet but capable is what you're able, I'd recommend any leading graphics card but with a custom heatsink and fan setup, Look for a large copper heatsink to fit on the GPU and memory of your card, and then buy a 120mm fan seperately. The copper heatsink will efficiently take the heat away from your components and the fan will be big enough so that it will perform well without making too much noise.
You can buy miso paste to make miso soup at WEGMANS.
Black market
Buy them
Drug stores carry it.
walmart or brook-shires
Radio Shack or Fry's Electronics