A couple of tips: Factory steering columns with shifters usually have a neutral start switch built in. These are usually missing on aftermarkte columns. Although they don't advertise it, Ididit will add a neutral start switch to a column for not much money - just tell them how high/low you want it on the column. That switch also includes a terminal for backup lights, should you want them (I did).
Grommets for passing wires through a panel are usually designed for thin sheet metal - when wiring a fiberglass car, often the panel is much thicker and not always even all the way around. A short section of rubber hose glued into the hole makes a good grommet and provides some strain-relief at the same time.