Alright, Thanks for the advice.
Firstly, I would prefer a hard drive, but i just didn't want to ignore all possibilities.
When I get to the point I believe I will get a USB Hard Drive.
Now say I get a terabyte drive, would I be dumb to make a 250GB partition and then back up to another? as my access to multiple drives is limited by my funds.
And the reason Id use Dreamweaver in Windows is I use skydrive to store all my general files, pictures, and school work and I want to put development files in there too so i can be able to come home and use my desktop Windows rig to continue work on those files, as well as allowing me to test sites and program on different systems and configurations.
Would Mac Dreamweaver project files be interchangeable with windows versions? Is there another program which achieves this?