How to do Effort Estimation for a Python web project

I am planning a web based project that is going to be implemented with Python. The project is going to use lots of open source packages such as Django, Pushpin, Celery, RabbitMQ, ... What method would you recommend for effort estimation of this project? I have developed a list of components to be developed and their level of complexity. Can I use COCOMO II? I really don't like COCOMO II as it only considers Lines of Code while the development is not only about how many lines of code, it needs to consider time to integrate with other packages, algorithm development, etc. Any suggestions?