I've used that scanner setup connected to a Mac and the software was a combination of VueScan and Adobe Photoshop. Vue Scan ran the scanner, but I progammed scripts in Photoshop to batch save the files and do some crop/resize/save. The vue scan software was complatible with the import option in Photoshop. I still use Vuescan with my epson flatbed scanner. The only experience with Silverfast was using a huge flatbed transparency scanner for radiology films and it was on a PC. That whole setup was not very user friendly. For doing loads of slides, I would want to have the batch capability in Photoshop.
What computer are you using to run the scanner and save your files?