Safety is definitely a need, but I think the Bengals are playing it smart by waiting for the market to settle on Reggie, or for that matter waiting for the market to pick up on Reggie. It doesn't look like any team is all that interested in paying Reggie what he wants. As much as I would like the Bengals to sign Reggie and move on from Crocker, I have a feeling that there is something else at play here. For example, if the Bengals happen to sign Aaron Ross tomorrow after his visit, that would leave them with Hall, Ross and Clements at Corner. Odds are Clements would settle in as the nickel bank, which he played a lot of during 3 WR sets. Clements also has the size to match up against some Tight Ends. It's possible that the Bengals may sign a corner or draft a corner in the 1st round and play Clements as a hybrid nickel back/free safety. Bengals may also be looking at Mark Barron in round 1 which would explain why they haven't aggressively pursued Nelson (although two phone calls in two days is as aggressive as the Bengals get at times).
I think the more important signings would be Anthony Collins and Manny Lawson at this point. Collins is invaluable as a backup tackle. He deserves to be paid sufficiently. Manny played up to standards in his first year in the system. He's young, can guard tight ends to a certain extent, he's respectable against the run and he can get after the quarterback. Let's get those two signed.
Ross has potential and can bring some playoff experience to the secondary. He's very inconsistent but worth a look. Bush and BGE are also definitely worth a look. No reason to argue that they have no breakaway speed, neither did Benson. We need a back that can convert a 3rd and 4th and one. Benson could not.
Don't know much about Jacob Bell, I would like to see them look into Hutchinson, Steinbach, Gallery, Jake Scott. They may have some left in the tank. Otherwise, it makes too much sense to at least draft DeCastro or Glenn if they are there at 17.