I bought a few things from the site Retro Innovations of Jim Brain.

6540 Rom Adapter:

• This PCB converts the MOS 6540 DIP pinout to a JEDEC standard 2764-27512 EPROM pinout.  The optional 5 upper address lines are available via pads complete with provision for pullup resistors (10K).

Commodore IEC Disk Drive Cable:

• This very short cable is useful for my second Ultimate 1541.

Retro Innovations ROM-el:

To program the ROM-el chip by Retro Innovations you need a Adapter. The ROM-el chip uses a Atmel flashrom AT49F001AN (128K x 8) and we must build an adapter that converts the pins of the 2364 PROM Commodore 64 Kernel, which is used in ROM-el chip, to the original state of the chip AT49F001.

After this work, you can use the Willem programmer to program the FlashROM with one or more C64 kernel.

Autopsy:

ZoomFloppy is an USB device for connecting Commodore disk drives to your PC. The ZoomFloppy is an improvement based on XU1541 from Till Harbaum.

Nate Lawson and Jim Brain teamed up to produce a professional product. This controller will support IEC drives, IEEE-488 drives and a user-port connection for parallel.

source: go4retro.com ieee488 beta software docs & firmware