Yea, the Chaos Druids are probably your best bet for being so close to a bank. The Men in the Edgeville Hut or Seers Bar also work, but they don't drop nearly as many herbs. I've collected herbs in the Edgeville Dungeon for many hours, and only one attempt was made to PK me, which failed miserably. Just bring a quick teleport method; whether it be a Glory, Ring of dueling, tele tablet, ectophial, etc. Also, a bit further from a bank (but close to a Fairy Ring) are Basilisks in the Slayer Dungeon. Assuming you have 40 slayer and a mirror shield, they drop lots of high level herbs, nats, and water runes, along with some alchable drops. Have fun herblore'ing! ~Lunar