Digital BW, The Print

Does anyone know of a filter for photoshop that will simulate film 
grain and let you pick the size of the grain-balls? I have a bunch of 
b&W infrared negs that have a dark blotchyness in the clear skies and 
need to somehow get rid of it. (Too much blotchyness for cloning) I've 
tried selecting, using gaussian blur and then gaussian noise, which 
works pretty well, but it's only one size. And you can see the 
difference next to the larger size. And the grain on these negs is 
pretty large. I also tried the Film Grain filter under Artistic Filters 
and it doesn't seem to give you a choice of size of grain, either. 
Maybe there's a third party one out there I don't know about.

I think it happened from the development, somehow, not in the scans, 
because I can see it in the contact sheets. These negs are from 
Cambodia, and I'm not going back there any time soon, so I'm desperate 
to find a solution. ANY suggestions will be gratefully accepted!! 
Thanks.

Barbara White
http://www.barbarawhitephoto.com