Hello! I just heard back from the folks at LightZone. I am really impressed with their personal support. Nice product. Good company.
I had scanned 4x5 B&W at 2400 spi on my Epson 4990 and created a 180 MB 16 bit file. It would have been about 3 times larger if I had scanned in color in order to only keep one channel. My 1 gig of RAM was too low to use LightZone for this size file.
Unfortunately, I cannot physically install more RAM on my P4 laptop, so it doesn't look like LightZone will be an option for me until I upgrade my system.
In spite of that, for those with more RAM memory on their systems (or work with files under 100MB), I encourage them to try the program. I really like it. And best of all, the company's support was superb. Best regards.