Jim Holden is absolutely right - sorry I didn't heed his advice when I met him. Originally ordered mine as a roller then had zero time to build it and switched it to a turn key - have regretted not having the build experience ever since. The regret does subside when I drive it though.
The wait is valuable, albeit painful. It lets you consider carefully all of the options (of which there are many). ERA is great to work with as well - true craftsmen.
I WILL build the next one (GT40).