Advice on what I should be looking at?

Javascript has its downsides (can be disabled by client) it does have some advantages you can't get with PHP. PHP alone cant:
- Measure the duration of last visited page. With PHP you only can determine the time difference between 2 visited pages. If you have some fancy 1 page website thats scrolls alot you cant measure any visited times at all.
- Detect screen size of the client

I have spend many and many hours creating my own PHP based statistics in the past because I don't like Google's ambition to know everything from everyone. But it always felt the results came up (very) short compared to Google Analytics. Since more and more clients wanted better statics I sadly decided just to give up on my own project. I still don't use Google on my own website but I do for all my clients. It saves a lot of hassle ;-)

If you don't want to give Google any more data you can use Piwik, an excellent self hosted alternative.