The only combo slot load DVD-ROM/CD-RW drive I have seen is in a laptop at Best Buy by vpr Matrix:
http://www.bestbuy.com/detail.asp?e=111 ... 490&scat=0
Who makes the combo slot load DVD-ROM/CD-RW drive is something I do not have an answer to, possibly Pioneer? Afterall, Pioneer does have DVD-R drives that also records to CD-R/CD-RW media as well.
Slot load drives are nice, I have an older SCSI Pioneer slot load DVD-ROM drive and CD-ROM drive. True it pulls the discs in by the edges, but I have seen "scratched" discs on some occasions.