Gabbys might be an ok species to work with as a rookie. I think there are much better species that you could start out with, but of the species you listed as wanting the gaboon might be your best. Although most of the time they are slow and almost ball python like, they can react very quickly. I know a guy who sold one of his baby gaboons to a lady in California, who decided to free handle her's and they found her dead days later in her house. They litterally had to scrape her of the floor. This girl had experience with hots and work at the zoo in California. So dont under estimate them. Also there is a pic on Venom-center.com of a boomslang bite, it might make you think twice before you free handle one. Fer-de-lance are very dangerous. Be very careful when working with them. The are one of the most dangerous species in South America, killing more people then any other species there. My good friend has a pair of adults, and they a one of the most aggressive/fast snakes he owns. I would rather mess with his spitters then the fer-de-lance.

My personal opion is that you are jumping into things quick. Remember that hurrying hurts. Make sure you learn as much from your mentor as possible, before you mess with some of the species you listed.

Matt