You are willing to turn and run Windows 7 64-bit on Mac, but no way would you go with a PC? even though Windows on Mac is not as reliable or run as well, and thermal sensor / fan control is somewhat lacking....
The ideal would be a sytem with Quadro 4000 for one, something like a Mac Pro workstation rather than laptop. MacBook Pro w/ Nvidia 330M or wait for (next fall?) when systems with Sandy Bridge processors and graphics are out in full would be nice, whether Apple or others.
Google. SolidWorks system requirements; threads here over the years listing SolidWorks. Also, a number of reviews take the MacBook line to task and review it to see if it would be a suitable Windows laptop (Ars, Anandtech, nuber of others).
The Quadro 4000 ($1200 / Mac Pro only) would kick butt.
But Yes you can do it. Just not stock 13" MacBook.
Don't know what price you get but this is price / performance I would go for:
http://store.apple.com/us/product/FC846LL/A
what Google would tell you about "Solidworks MacBook Pro" -
http://forums.macrumors.com/archive/index.php/t-773631.html
And an old thread from here.
http://discussions.apple.com/thread.jspa?threadID=1264059