'rather stunned" is correct and usable in written English.
You can use it to emphasize the degree of surprise or shock experienced by someone. Example: I was rather stunned to find out that I had won a vacation to Italy.
He looks rather stunned by this, and poignantly proud.
Sharapova, meanwhile, slumps into her chair and understandably looks rather stunned.
The lights go down on a rather stunned silence: the audience, if not the man who played him, loved String.
It's not much, but it's a little more promising again after the rather stunned looking performance since the goal.
In lieu of a transcript, here is how The Guardian's live blog recorded it: Watson now asks a rather stunned Murdoch whether he is familiar with the mafia.
In the N.B.A., we suddenly have the Heat becoming the bullies in a series with the Celtics, who were rather stunned with that turn of events in Game 1, writes Ken Berger on CBSSports.com.com
By the time the FA decision was made, we were ready and able rather than merely stunned and naïve.
These things came and went very rapidly; what was left was rationing that continued in one form or another until 1950, and, if you read contemporary reports, a populace that was a rather strange combination of stunned and bored.
No matter, too, that this time they parted in stunned disbelief, heads shaking, rather than in acrimony, recrimination and spite, as at Cancún in 2003.
Megan's suicide — for anyone who had not already heard, or been forwarded, the story (often with a stunned "OMG") — had not been a hoax; rather, it was precipitated by a hoax, involving a boy named Josh Evans.
Williams said that he was "stunned" by NPR's decision and questioned whether NPR understood, "that I'm in fact challenging Bill Reillylly" rather than bowing down to him.
