Digital BW, The Print

I have a Hasselblad Xpan, Nikon Coolscan 4000ED (with roll film
adapter) and Canon 9900F scanners and Vuescan.
 
I want to get a 16 bit Coolscan scan of the Hasselblad negatives.
 
The only way to do it seems to be a photomosaic program.  But
Photoshop can only photomerge 8 bit grayscale images.
 
Can anyone recommend a photomosaic program that can:
 
- merge 16 bit grayscale images with a TIFF output;
- ideally do batch merging
 
And can anyone suggest another solution? (other than upgrading my
scanner or using the 9900F!)
 
Thanks
Gareth