First, welcome to the forum!
Second, I'm in no way an expert, although, I've come to believe that if one does adequate research, it doesn't matter that much as to which kind of bird you get.
By adequate reserach, I mean not only internet searches or printed research material, but speaking to experts. Avian vets (not regular vets, but one who specializes in birds), rescues, breeders and bird clubs are good places to get first-hand information. Also spend time with the kind of bird you want, if possible. Greenwings are absolutely beautiful, but they're big and that beak can be intimidating. The last thing you want is to get your new baby home then be apprehenisve around him because of his size. Parrots are very intelligent and will soon learn who's "top bird" in the relationship, so spending time with an adult could help you see exactly what you're getting into.
Third, as far as time alone while you and your wife are at work, as long as your parrot has enough to stay entertained and stimulated, it should be fine. My husband and I both work, and our youngest has 2 years of high school left. So during the school year, our birds are in their cages until about 4:30-5PM. Of course, as soon as I put my purse down, the cage doors are opened and they're out to spend time with the family until bedtime. We try to make up for this on the weekends when we let them out all day. But they have plenty of toys and we leave the radio on while we're gone.