I just wanted to know before I buy, do these games use DOSBox to run under Windows? And if so it it possible to enable the DOSBox scan-lines video option with this GOG version? Also are the core games based off the CD-ROM or Diskette releases?

I can answer the first question: The games do use DOSBox. It should therefore be possible to enable the scan-lines video option. (Look for a file with a name like dosbox[game].conf and edit it.)

Re: CDROM vs diskette

I have never seen the CDROM version of the games. However, when Iaunched GOG EoB 1, it looked just like my old diskette version of EoB in the intro and the part of the first level I played. If the CDROM version differed by that point, I'd say this is the diskette version.

I have one of the CD Forgotten Realms collections. As far as I can tell, the version on the CD is the same as the floppy version. Different installer, but the same overall files.

Flynn

AFAIK of all the games in the three collections only Menzoberranzan had a specific CD version that was different from the floppy one.
The floppy version was missing several sub-quests and features. The cluebook explains all the differences.

From reading the three EOB series cluebooks, there are no differences: the CD versions were just the floppy versions on a CD (if you know what I mean :) because by the time the compilations came out it was a lot cheaper for companies to put a CD in a box than stuff it with a dozen floppies.

EOB3 actually came on 4 floppies. Not quite a dozen... ;-)