Yep, it's a wheels #16.. Thankfully all my bikes use the same hanger so I will always have a spare, well OK two since I bought a Wheels #16 as well.
The official
Cannondale model ,
Wheels MFG . Pretty much the same price so take your pick. I am pretty sure Jenson , WorldWide Cyclery , and Universal Cycles have them as well, at least the Wheel MFG #16.
I am not surprised that it's a bit bent , I am surprised that your LBS doesn't have a derailleur hanger tool to straighten it out. I guess they want you to buy another one.. Unless it's seriously bent, which from the picture it is not, they can be straightened out. I've had to do it on my M700. Go figure that after nearly 30 yrs it was tweaked a bit. Took me about 5 minutes to check it with the tool and fix the issue.