You need drainage that is a must .I would go with a m-9 root stock, You will need to stake them ,but well worth the trouble . Jonagold Decosters are a great way to go ,also their are some early braburns that will work here . also Honey Crisp . To keep your trees in good condition apply lime every year and there are good organic sprays out there but the best is Lime Sulfur. BTW apple maggot will attack any tree, Apple maggot love all apple trees . You can either use traps which is what we do, or safercide insecticide which is organic.