Fast scanner with feed

I'm looking into introducing a fast scanner with a considerable volume paper feed to an already existing Rapid Data Entry (RDE) application.

Essentially, I want to introduce a new feature into the current process, so that the operation works like the following cross functional flowchart (double connector represents parallel process, connector with large triangle means "pass control to"):

Attachment 9713

Notes:
- As denoted, at the end of the process, the application automatically instructs the scanner to feed a new form.

- The whole process above is expected to have a minimum time of 5 seconds (and a maximum of 3 minutes).

Requirements:
So, I need a scanner that can at least scan a form (size A4) in B&W in under 5 seconds, that can hold a considerable number of forms in its feeder and that has a programmable API I can use to instruct it from my RDE application.

Any one of you have any recommendation?

Man, years ago we had two 40 ppm scanners at a Gov't office. These were Cannon but I don't recall whether it would do A4 nor what the model number was. I do remember that it would handle about 500 pages in its input side, but the output just kinda through the pages in the floor (we eventually put it on a stand and put a basket underneath it). Boy was it fast, though.