Meghan and Doug,
The does were New Zealand's and the bucks California's, so you were both right. Using two different varieties leads to hybrid vigor. The picture of the doe in the cage with the half grown kits that is a Florida white, look like New Zealand but smaller. It was an experiment but saw no good reason to keep them.
You will get extra kits.....I have had the does throw up to 21. I would make sure to always have two does bred the same day, that way if one had a big litter and one a small litter I would swap kits to balance but never let them have more than 8 max, 6 is ideal. It is hard to cull out tiny babies but having the mother try to nurse a dozen kits is very hard on her and all the little ones. Be careful some of those does can be very protective and rabbit bites HURT!
You do have to be careful with rabbits and too many wet greens. While they love them it does tend to mess up the balance in their systems which leads to the runs and can lead often to a very quick death. When you say horse feed/timothy grass is it dry hay? If so it is great for them and can have it constantly if you want to. I had hay racks in the pens mounted on the walls. Green grass would worry me a bit. If you stick to just dry foods, pellets, hay, fruit tree sticks you will not have issues. Give them a bunch of green foods, problems. It seems counter intuitive but that is how it works.
A ramp would work.....anything you can do to keep the coons out from under the pens.
How are you watering them? I started with the trigger bottles and very quickly disposed of them. I ended up using irrigation line, a water timer and regular glass bowls. The timer would kick on 3 times a day for 1 minute and refill all the bowls with enough extra to wash them out.