Thank you all for the feedback, tips and suggestions! Based on the responses, I think 100' of chain may be overkill, so I think I'll keep it to 60' and get another 150' of rode spliced in on the backside. That should be a decent enough combination of weight, flexibility and scope to handle our type of boating. Over the winter, I am considering adding a mantus or Rocna to some additional piece of mind (and easy setting), but for now, I think the chain/rode ought to improve our holding power enough to not warrant the upgrade.