I use a Xerox DocuMate 152, which easily would handle 100 pages a day. It does full duplex, full color scanning. Also has an auto document feeder.

As far as work flow...I am horrible at setting this up, and to this day just have the scanner setup so that when i hit the scan button, it scans everything in the adf into one pdf, upon finishing scanning it pops up this pdf in acrobat so I can save it to whatever I like.

This way my work flow looks like this:

1) Mail/Document/Whatever is received.

2) Item is opened and scanned. One full envelop/document at a time.

3) After scanning all the things to be saved, I head over to the computer and there are a bunch of PDF's open on the screen. I go to each PDF, see what it is, and save it appropiately to my file structure.

I use to use omnipage, but it was just too complex, I wanted something very simple and easy to use.

Good luck, report back with what ya ended up doing for me!