You could probably use a petite Aviator Harness for your lovie! The only thing is that if your bird doesn't love being touched, it may be difficult to train and take much longer than you anticipate. You could also always invest in a small, clear carrier as well if that harness doesn't work out. I'm personally looking into getting a Celtei Pac-o-Bird backpack. One of our members, Kiwibird (April) has one that she decked out and it's awesome!:
http://www.parrotforums.com/cages/42946-kiwi-s-carrier-relined-like-pimp-my-ride-parrots.html
There's also the option of a Flight Suit, although I have no personal experience with them and I don't know if they make them small enough for lovies.