I think i might have found a possible great defensemen for the Senators. Jason Garrison of the (until July 1st) Florida Panthers. He is 27 years old, 6'2'', 218 pounds.

Here's what LitterBoxCats had to say about him:

Jason Garrison:
Garrison played 1825 minutes over 77 games (37-23-17, .591) for the Panthers. We always knew he was a solid defenseman, but this year he came out of nowhere with a ridiculous cannon shot to set the record for Florida defenseman scored goals, with 16 on 168 shots, along with 17 assists, a plus-6 rating and 32 penalty minutes. Rating: 91.0

I think if BM goes after him as soon as he is available with a 4 million for 4 years. Plus resigning Kuba to a 1 year contract at the same amount as last year. That would give us: Karlsson, Kuba, Cowen, Garrison. With Phillips and "insert name here" as the bottom six. That would give time to the rookies to develop a bit more in the minors or for injuries. I'm just not sure why Tallon is not resigning him right now.