I use AdGuard Pro in combination with StevenBlack/hosts [0] and a custom DNS. This is used for system wide (not just Safari) ads/tracker blocking. Adding custom filters as and when required.
I like weblock (I believe were talking about the same by Futuremind) but I prefer their other app Adblock (I posted a small quib about it ~15 replies up from this reply). You can also, if you want; copy the PAC weblock sets up for you, host it yourself on github and then set it up as your own proxy for whatever wifi you connect to.
- [0] https://github.com/StevenBlack/hosts