If you have money to spend on the Bot, then go with Robotzindisguise. He currently has a Mage Training Arena bot and a Black Smithing bot, both of which work really well.
Robotz website, where you can get the bot, is www.robotzindisguise.com
You could also contact him here on sythe, his username is robotzindisguise.
If not, I suppose RsBot is a far less safe alternative, however it has many more skills available.