best practice to move files from one farm to another?

Question

In our project we want to move our code changes from DEV environment to other environments (QA / PROD). Code changes include:

1. JS / CSS / XSLT / Images
2. WSP packages for C# code (custom webparts)
3. Web part pages

We are looking for powershell scripts to handle these tasks, because we are not supposed to do anything manually in PROD environment. So we are not allowed to use SPD as well.

We have got powershell script to upload JS / CSS / XSLT / Image files to destination farm. We are using powershell to install WSP packages (custom webparts).

But we are mainly strugling with web part pages. Can some one tell us what are the best practices to move files (mainly web part pages) from one environment to another?

We are using Publishing site in SharePoint 2010