really interesting read and I will be following this. We're currently building our 2nd track car and have picked a 180. It is the 1st 180 we have worked on so your thread is a bit like a shopping list for us and we can see what bits work and how well. This will certainly save us a lot of time and money.
Our build thread is here
http://www.themgzs.co.uk/vb/showthread.php?t=22733
One thing we did invest in was a very cheap video camera for in car videos...get one for your next track day....would love to see some in car action of yours