I heard an issue about public insider trading buying info is that it is delayed usually by weeks / months.

Are there any sites / resources for finding insider buying that are considered to be the best?

SpecialTed 

I heard an issue about public insider trading buying info is that it is delayed usually by weeks / months. Are there any sites / resources for finding insider buying that are considered to be the best?

This a an old and good one but not free

https://www.washingtonservice.com/

You can check out FinViz.com which is free. They have an insider section that shows SEC Form 4 filings.