SP088/SP089 with Viking crusaders is what I run and works wonders. I would give this thread (link below) a good read. Covers all the questions you may have, definitely helped me figure out what setup I decided to go with.
https://www.mustang6g.com/forums/showthread.php?t=39576
Comes with the needed fuse box/Ecu relocation harnesses.
From the experience I have heard so far from their s197 kits are that fitting the kit does take some patience. Buddy of mine runs their s197 kit with the included 60's and is making over 1100whp and swears by their kit.
ON3 has recently announced via Instagram that the first batch of Gen2 kits are being shipped out. Anyone on here waiting for theirs? Really excited to see how this kit works out.
Ill be ordering a parts box from you guys very soon and am also hunting for a clean head unit. What should I look out for when purchasing the head unit, i.e what parts SHOULD it come with it?