Just be aware that even though a card might be sold as OHCI/EHCI compliant, that will not always be the case. I bought a "OHCI/EHCI compliant" USB 2.0 card for my Wallstreet a while back, and found that out of the box, it would not work with OS 9 or OS X at all. (in fact, OS 9 "recognised" it as a SCSI card!) I put it into my Compaq laptop which recognised it as having a VIA chipset (it didn't mention ANYWHERE on the box what kind of chipset it had, nor did it come with an instruction leaflet), and then found a driver on VIA's website that allowed me to use it.

Under OS X, the card works perfectly with the VIA drivers, but to my understanding, if it doesn't work straight out of the box with the Apple drivers under either OS 9 or OS X, then technically its not OHCI/EHCI compliant. Just something you need to be aware of! (after this I won't buy a USB card for a Mac unless I know exactly what chipset it has)