I personally only use free scripts (RSBot) and paid bots from rsbots.net, but I'm starting to hear bad things about rsbots, so it wouldn't hurt to try them. Their website looks pretty decent, and they aren't new so chances are they pretty legit.
I'm actually planning on buying one of their bots when I sell my WoW account, so if you haven't already bought it yet, I'll let you know how it is.
As for rsbots.net, I personally haven't been disappointed with them. I ended up paying for all of the bots when I only wanted 3, and they gave me a full refund. I've botted for over 20 hours straight using their bots and still haven't been banned.