Watts? Ohms? I'm lost.

Watt is a measure of power.  Ohm is a measure of electrical resistance.

All name brand home theater receivers put out more than enough power (wattage) to power a resonably priced set of speakers.  People who get hung up on watts are usually from the car audio world.  It is the least important spec of any receiver.  And it is almost that useless in the car audio world as well.

The impedance of the speakers is a little more important but not that much.  Most home theater speakers will be rated at 8 ohms.  Some will be 6 ohms.  Few will be 4 ohms.  If your receiver is rated to drive a 6 ohm or higher load, then it doesn't matter if you have a mixture of 8 ohm and 6 ohm speakers.  You should also read personal reviews of the receiver you are looking at.  I bought a Pioneer VSX-1014 a few years ago because I needed a receiver that would drive 4 ohm speakers.  The receiver is only rated to drive 6 ohm or higher speakers but many, many people were successfully connecting 4 ohm speakers.

You should look for speakers that sound good to you and at least the front 3 being timbre matched.  Your receiver should have all of the features and connections that you need for current and future sources.  Move ohms and watts to the bottom of your things to look at.

I second what Robert says.  Forget about watts, it's practically a made up measurement and means nothing.

No, this has nothing to do with technical specs and everything to do with how the speakers sound.  Timbre (TAHM-ber) describes the over-all sound quality, the "color" of sound as produced by a given speaker. 

Sound "quality" or "timbre" describes those characteristics of sound which allow the ear to distinguish sounds which have the same pitch and loudness. Timbre is then a general term for the distinguishable characteristics of a tone.

The reason it is important to timbre-match the front three speakers is that it is distracting when the sound pans across the screen in a given scene and it changes as it moves from speaker to speaker.  It the music suddenly sounds more brassy when it jumps to the center speaker, or the dialogue more brittle, it can take you out of the scene.  And there will always be differences in tone between speakers that aren't virtually identical.

The only practical way to assure that your front three speakers are timbre-matched is to buy three speakers from the same manufacturer that use the same drivers, materials and enclosures.  In theory you could buy two speakers from two different companies that use exactly the same drivers (or drivers that are acoustically indistinguishable) and cabinets made of the same wood and assembled the same way, but realistically, that isn't going to happen.

Either buy three "model X" speakers and lay one on its side to be your center, or buy a set of three front speakers designed to work together.  My Atlantic Technology speakers have a center speaker that is basically identical to my front left and right, except that the drivers are mounted horizontally and the speaker itself comes with rockers and a base to enable me to tilt the speaker up or down to get optimal sound in my room from its position on the "bridge" of my home entertainment center. 

Regards,

Joe

P.S.

Your thread title reminds me of an Abbott and Costello routine, "What's volts?", from the film Who Done It?  Similar to the classic "Who's on first", "What's volts" was actually developed by the pair on set during the making of the film.  A google search should turn up a video clip of the bit.  (I can't seem to find a transcript of it anywhere.)  I'm at work and can't access streaming video sites, and don't know how to embed video in a post anyway, but if you find the clip I think you'll agree it was worth the bother.  (The film itself is one of the team's best efforts, very funny with a decent mystery at the center of it.) 

Regards,

Joe

The SVS speakers are most certainly timbre matched.  They are also fine quality and great bang for the buck.