Phhhhsssst. I stick my tongue out in the general direction of Sonnet's IDE cards.
And suggest the Acard 6280M or 6880M. I'm using the 6280M in my main machine and I often boot it into 7.6.1 where it works just fine. Also 9.1 and points in between.
The 6880M is just a 6280M with a couple extra whistles to support RAID. The beautiful thing about the 6880M is that if you build a RAID with it, you'll have access to your RAID both in OSX and in OS9-minus.
Whereas with OSX's built in RAID functions, you can only access the RAID in OSX.
The 6280M and 6880M both have large drive support. And I've used a DVDRW connected to one without issues. However, I'm not sure if I've ever used a DVDRW on the 6280M with 7.6.1. Maybe just 9.1. But my DVD-ROM drive works fine under 7.6.1.
Toast 5 is the last version with Classic support. After that it's all OSX only.