How about straight up:
Shattenkirk
for
Bish
Both 1 year left on their contracts and UFA afterwards. The difference in cap hit is about $1.7M which looks like the Blues can absorb and the Lightning get a bit more breathing room to sign RFAs. Bish is from St. Louis so he would most likely waive to go there. St. Louis improves their goaltending for a solid run at the cup and Lightning get their RHD PPQB.
Shattenkirk
for
Bish
Both 1 year left on their contracts and UFA afterwards. The difference in cap hit is about $1.7M which looks like the Blues can absorb and the Lightning get a bit more breathing room to sign RFAs. Bish is from St. Louis so he would most likely waive to go there. St. Louis improves their goaltending for a solid run at the cup and Lightning get their RHD PPQB.