Querying Seismic Databases
Unless they are large or famous earthquakes, I doubt you will find the waveforms for specific earthquakes.

What you will find is a ton of seismic data: http://earthquake.usgs.gov/data/?source=sitenav

which you can request. Once you have requested (downloaded ect) the waveforms (probably in seed format) you will need to analyze the waveforms themselves to find specific earthquakes (request data from a time when you know there was an earthquake) and find the p/s/love ect wave yourself on the seismogram.

To read seed data, you can either find a matlab code or write your own! (Im sure there is a python equivalent at this point.)