The driver install download would likely be about 500MB, at least that's what I have...
There's a good chance that a torrent download of the OS X installer may not have the Windows setup, as it's on a hybrid section of the DVD. Might work, might not work.
A Snow Leopard DVD is only $30, and a lot less bother than trying various downloads. You would also have the advantage of having both an up-to-date version of OS X, and have the various utilities that you might need to maintain your MacBook properly.