hard to say without Ned having an NHL body of work to compare to. He's rated pretty high but I'm not doing this 1-1.
Really, I'd much rather move Demko to fill a need on your team and get Ned added almost as an add on to the main deal.
Also curious as to what your overall G situation is like - who else do you have?
if you could add a team sig & give league settings etc so we can provide overall recommendations/advise ..