Thank you very much for reaching out. I have followed yours and other builds over the years until I made my move. It is good to know about a good set of schematics being available. I have declined the Koso and still in search for a dash. I am not sure what the final LS motor configuration looks like. I think when I know the engine management I'll decide on the dash.
Looking forward to have many conversations on this forum...
Congratulations on your new SL-C. I'm sure that you will find the forum helpful. I'm in year 4 of my build and I am planning to put mine on the road this season in Indiana. I've been offering a wiring diagram drawing to the new SL-C builders and it's been well received. I sell a .pdf version of the drawing for $20 via cash or PayPal if interested. Recent purchasers are Dan Carter and Cam. The drawing is set up for the LS ECU and Koso gauges but is easily adapted for and of your planned modifications.
If you'd l can email you a clip of the diagram so you can see the detail. Additionally, I have other part assemblies in development.. If you have questions just ask, I'm well in tune to the SL-C and am making many modifications that you can see on my build.