Without using a green screen background to key the footage… you certainly are making your project harder than you should.
But… if you must go the rotoscoping direction. The best software to use may be Imagineer’s Mocha (full version…not the AE plug-in version)… but, a lot depends upon how you shoot the footage… if you plan it right you might be able to do the rotoscoping with AE or a less expensive rotoscoping software.
No matter the choice of software you use to help you with your rotoscoping… rotoscoping is going to be more time consuming and difficult than using a properly set up green/blue screen as the method to achieve the results you are looking for.
In fact, depending upon the character’s movements, rotoscoping may be too difficult to achieve silhouettes that are useable… for example, rotoscoping leg movements can be very difficult and hair can be almost impossible to rotoscope.
Bottom line, rotoscoping dancing people (specially with leg movements and hair included in the frames) will be a VERY difficult process even for a very experienced rotoscoping specialist. I would seriously rethink the idea of not using a green/blue screen keying process.
Joe Moya