at first, everyone of your team needs to know HTML, CSS and the basics of PHP. For such a project I would work with includes to reduce the massive rewriting of code.
It is hard to say, if it can succeed, because it is at first matter of a good project planning and then a question of the experience of the peolple.
When you have the project really well planned (project planning is a science for itself) and your team is average, than you can realize such a project within 3 month without a problem. 3 month, 4 people, that makes more than 2000 man hours. When it is a full time project. When you do it only two hours a day with totally unexperienced personell, just forget it and make something smaller.
but when there are specific questions for problems, or for the project planning, just pm me.