Well, I am accumulating the lead for that army myself (tho actually something of a Late Roman force, morphing and expanding.) with most of the figures coming from Essex, Old Glory or Outpost. Don't think you can go far wrong with any of these three (contrary opinions invited).
Were you in USA, would urge you to Email Mike Sanderson - email@example.com
- who is holding private sale, _many_ bags of unpainted Essex figures, very reasonable prices, great fulfillment service. But what postage to Oz would run...