PokerTracker

Anyway to get a stat made for rake back BB/100 + BB/100. And to have these stats only apply to a certain site, so we can we can have the correct rake back percentage for each individual site.

You can do that with a custom statistic - see this guide for the basics on custom statistics creation and this guide for a deeper walkthrough. While the latter was written for PokerTracker 3 and the user interface is different the techniques still apply to PokerTracker 4. There may also be some similar stats if you search this forum or the Download Warehouse and you can edit them if they are not exactly what you are after.