I've used MusicMatch for over a year. I'd like to steer you away from it for what you plan on doing. There is even a MM employee in the empeg BBS that doesn't use it to rip. I'm sure the quality (esp. at the bit rate you are talking about) will be great, but the ease of use isn't.
I really recommend using Audiograbber (or EAC if you are using Windows2000). What is nice about these programs is that you can feed it cd after cd after cd real quickly. These programs will rip to a .wav. You can feed them a lot of CD's in a short amount of time. Then, while they are encoding the .wav's into mp3, you go to bed or work!
It took me nearly 6 months to encode my collection to 160 (then 192) using MusicMatch. I've been re-doing my collection to VBR LAME with a mix of AudioGrabber and EAC and have done 1/2 of my collection in about 5 lazy weeks. Not bad!
Setting these programs up takes more time. But it is worth it. You can set them to do 320kps CBR (like you are doing with MM) and have them auto create a .m3u playlist file too. I just feed them CD's, touch up the FreeDB entries, and click the "rip" button.
They handle comilation CD's more intelligently too (usually correctly assiging the artist name).
Again, I used MusicMatch (and still do to play mp3's or edit tags) but for MASS ripping like you are talking about - I would take a day or two to research it and in the long run - save tons of time.