[rules-users] Stateless vs Stateful

We have a batch application that will have 50 - 60 rule sets, comprised of 5 - 75 rules each. We'll run a group of individuals through the rules and potentially qualify them for various awards. We'll insert 10 facts, each containing a unique set of attributes which will be used in the rule sets to determine potential qualification. The batch process will insert one individual's data (10 facts) at a time, fire the rules, and return the results. The data on the objects inserted will remain static. Also, in the future, we'd like to integrate the rule sets with a 'what if' web application, wherein the individual can modify the input data, fire the rules, and see the results. Given this, can you recommend whether a Stateful or Stateless knowledge session is more appropriate than the other? Is one more appropriate for a batch vs online application? Thanks Rob