Negolien, it's not as simple as extra tweeters... Yes 3 ways means a mid range and 2 tweeters, but that's it's more complex than that. The more "ways" the speaker has, the more that the frequency range is split. For example, in a normal 2 way speaker or component speaker, the midrange handles the lowest frequency range the speaker was built to handle while the tweeter handles the higher frequency range. What this equates to is simply more clarity in your highs since each range is split. In a 3 way, there's usually a normal tweeter and a smaller tweeter that handles the frequencies we can barely hear like 17K-20K. It is said the average human can hear between 30 and 16,000 hertz.
Here's a picture you'll find interesting.
As far as the amp, why not go for a 4 channel at that price point? For $250, you could easily get a 4 channel. You don't necessarily have to use all 4 channels on a 4 channel amp. You can bridge them or only use 2 or 3. It doesn't really matter. Each channel is capped.
This is the Alpine MRX-F65. It's 100 watts per channel @4 ohms.
http://www.onlinecarstereo.com/CarAu...FU_NOgod40YA8g
Also, instead of Crutchfield, check Sonic Electronix. It's the same thing as Crutchfield, except it's cheaper and based in your state of California.
http://www.sonicelectronix.com/searc...Alpine+MRX-F65
Here's the Crutchfield link if you want it
http://www.crutchfield.com/p_500MRXF....html?tp=35782
If you like Pioneer, here's a Pioneer amp that puts out 100 watts x 4 channels as well.
Crutchfield
http://www.crutchfield.com/p_130GMD8...82#details-tab
Sonic Electronix
http://www.sonicelectronix.com/item_...SearchClickout[query_id]=22007280&SearchClickout[Ignore]=1