If you don't have even information at that level, feel free to tell him that you want some time to think and pray about it (that is, if you're not sure at that point that you're not interested).
Then — in addition to actually thinking and praying about it — ask one of your pastors or elders whether he knows him and what he thinks.
The idea is to remove that period of confusion or vulnerability for the woman by being forthright about what level of intention or commitment exists (a la 1 Thessalonians 4).
You probably won't know at this stage how things are going to ultimately turn out regarding marriage (that's why you date), so you need not communicate that right away.
Remember, your intent at this point is not necessarily marriage — and that's not what either of you are committing to at this stage.In my view, this establishing of intentions should be done near the beginning of any exclusive or romantic time spent together — preferably within the first two or three "dates" during a deliberate conversation on the subject.