I like my Garmin 705 so much for brevets - I can set it on a really, really low backlight and see it all night long - plus, I load the route ahead of time so it beeps to alert me for all upcoming turns. Makes seeing the cue sheet at night less essential.
Great idea on bringing lots of food. I had one emergency promeal bar, and was about 20 miles away from a control when I needed it. Broke it open, took a bite and was gonna nibble from my bento box. Sure enough, I hit a bump on a descent and it bounced out. Desperate, I turned around to go get it, just in time to see a car completely nail it - totally smushed. Guess there were some happy squirrels later that day. So, yeah, some backup food is a great idea.
Add a few hours to your battery life on lights - you never know what could happen that could throw off your timing and as you know, getting caught even for a mile without enough lights is really scary.
I wish I could come and ride with you!
For 3 days, I get to part of a thousand other journeys.