Audio Systems: Patio stereo, watts rms, speaker impedance

Question
I want to put a stereo system on my patio, with the receiver and a computer (to provide internet radio and MP3 files) indoors, attached to outdoor speakers.  The speaker wire will run through the walls.  I only need 2 speakers, so a 5.1 or 7.1 system is not relevant.  

I will buy new outdoor speakers but not sure what to get yet - still researching.  I'm thinking I can use an old-style (and hence cheap) receiver as long as I am able to hook it up the computer. Can I use any old receiver with new outdoor speakers?  Do I have to match the power output or can I just be careful with the volume?
Thanks,
Mark

Answer
For the most part, you can use any receiver with any speaker - the most important thing to make sure that is matched up is the receiver output impedance and the speaker impedance (4 ohm, 8 ohm, etc...). As far as the watts RMS, these are rated at full output volume, so unless you plan on really rocking the neighborhood out, you don't need to worry too much about that.