All capacitors tend to be labelled in the microfarad (uF), picofarad (pF) or nanofarad (nF) range. Conversion is:

1000pF = 1nF
1000nF = 1uf
1000000pF = 1uF

Picofarad capacitors tend to be notated by just a number.

I'm unsure about the type of capacitor you should get, but I don't believe it matters so long as you don't get a special design that does a different job (best analogy I can think of is using Zener diodes in place of Ge/Si diodes, which you basically don't do because it does a different job). And you should be able to get capacitors cheaply from a number of different online retailers - Small Bear Electronics I think are pretty good (just Google stuff).
Alright, but I still can't find capacitors in a small enough range. Would be okay if I just replaced those caps with ones that are slightly different?
Use same or very similar values.

For those small capacitors look into Silver Mica capacitors or Ceramic capacitors. These two types are non-polarized and come in low values.