David, don't let my own bit of confusion put you off the Deneb. It is a nice piece of "kit," and I am quite capable of going off course with even the best of instructions. Lloyd described the contents of the package very well. I'm sure I'll get my problems with the romupdates sorted out.
Darrin, if you followed the printed instructions letter for letter, you probably have the hardware hooked up right and the software installed. Now it's likely a matter of fussing about in Trident in your Preferences drawer. Took me a small amount of head scratching to enable the DMA controller driver, but not too much.
The CD-ROM problem takes me back to setting up my 4000 a couple of years ago. With SCSI CD drives on my other Amigas, I've gotten them to work using asimcdfs, and then used the CD drive to install OS 3.9. The 3.9 installation seems to upgrade the asimcdfs installation to cachecdfs, which I prefer because it allows longer filenames. I deleted the asimcdfs files later.
On my 4000 I use the same setup as you with the onboard IDE controller. I seem to recall that my asimcdfs approach didn't work out well for me, but I don't remember why. What I think I wound up doing was downloading the demo version of IDEfix and using that to get CD support going. After installing 3.9, I got rid of all the extra IDEfix files and the lines it added near the start of startup-sequence.