In your particular case, you should make 2 separate images: 1 of Windows partition and 1 of Mac OS X partition. If you made a complete HDD image, then you would get the same partitioning arrangement, which is not what you want.
For Windows, regular ghosting tools can be used from bootable CD/USB keys to make an image of the Win partition that you would then restore to the new and larger partition of your SSD drive.
For OS X you could indeed boot your OS X installer and make an image of your existing installation for subsequent restoration to the new and larger partition of your SSD drive.