ebay seller dlchief58 has them at pretty reasonable prices.
Unless you really want a quiet machine, the CF card and SCSI-IDE converter is a waste of money. I'd go for a fast 68 pin SCSI drive - the SCSI Nubus cards can mount them, whereas the onboard SCSI only takes 50 pin drives.
Fast SCSI drives can be noisy though. If you want a cheaper quiet option than the CF card, a SCSI-IDE converter and a Seagate IDE drive is worth considering.
There's a good list of Nubus video cards at http://www.lowendmac.com/video
How on earth can that be a "toss up"? It's a complete waste of money for speed you are definitely, not probably, not using.
There's a member here who has them for sale for about half that. Searchy searchy