I've just emailed Amigakit with what I want to do so will wait their reply.
I thought about the floppy drives as well and think the best way is to use the longest cable on my external drive (26") to route from rear floppy port to front drive bays then use 2 molex to floppy connectors to power both drives, will need a 5 1/4" to 3.5" mounting bracket for one of the drives too which I think I have knocking about. I've asked Amigakit how many molex/floppy connectors the PSU in the EZ Z4 has just so i can plan for all the kit.
Also realised after reading the Indi AGA MKII thread i'll need some ROM Risers for the FastATA if using the AGA MK II, Amigakit stock these though so put that in the email as well. Also want it all putting on one order and shipping when everything is in stock so I can have a fun filled day putting it all together