Well, the "underperforming" VIA IDE controller is actually just an issue of BIOS not setting it up right.
Use a DFI K6BV3+/66, and you'll get everything you wanted, including UDMA66 and up to 2 MBytes of L2 cache.
The actual speed gain from going UDMA66 isn't really worth that, however. And I really doubt that there are super-7 boards that do not have USB ... so you better just go shop for a suitable USB slot bracket to solve your problem.
Regards, Peter