They're ground birds and won't particularly like the ramp. They only go vertical in times of fear. It's low enough though they may still use it. If they don't try to build an intermediary platform so it's just a couple step up.
Absolutely no heat lamp for adult quail. Birds grow down feathers sufficient to the ambient temperatures they are kept in. If the heat lamp were ever to shut off in a power outage or burn out your birds would most likely die, unless you were right there and noticed it. In the case of quail there are very few places in the US that they would need anything beyond having their coop insulated with plastic sheeting to block out the draft. Keep in mind coturnix exist in the wild, primarily in Northern China and Russia. It gets very cold in their habitat. The only quail that are commonly kept that need protection from weather are button quail.
You'll need to use 1/2" x 1/2" hardware cloth around the sides, if you can fit a nickel through an opening, a predator can pull a whole adult quail through it. Cage raised quail will actually go investigate predators giving them even better opportunity to snatch their little heads off.
