Questions need to be asked before buying into the traceable idea :
A sack of coffee can be traced back to an individual farmer - 1 farmer. However, this needs to be agreed prior to contract to make sure the coffee is processed seperately. In addition, this requirement carrys alot of time, effort, legal documentation, quality controls - the list goes on - as so the price must reflect these costs. Quality is likely to be high.
Single estate / farm is easier to supply but is likely to attract a higher premium as the farm will have higher overheads. Quality is likey to be high.
Single Cooperative / village coffee is available but there will always be the small chance that coffee has been brought in from outside the boundaries specified. The qulaity can be good but not always.
Area - such as Brazil Cerrado - will give a generalised cup profile and probably more consistency in cup. The least expensive option in traceability.