I applaud you on your resolve not to clip, to let the bird fly, and to seek a harness to be able to take the parrot outside safely. Here's the harness I use with all of my parrots:
http://ParrotWizard.com/HarnessGo with the petite size. Choice of colors is red, black, blue, or green. I suggest green or red. Getting the harness and the mechanics of putting it on are rather simple. But getting the bird to be comfortable with wearing it and especially putting it on are a whole different story. I strongly advice anyone thinking about having their parrot wear a harness, first read my book and learn all of the taming/training requisites, and only then proceed to the harness training specifically.
Book:
http://ParrotWizard.com/BookHarness Training DVD:
http://ParrotWizard.com/Harness_DVDAnd here's some more free info on my blog:
http://TrainedParrot.com/Aviator_HarnessIf you get the book and harness from my site, I throw the harness training DVD in for free. It's easy to buy a harness but hard to actually use it right. So I hope you can use the information, your patience, and training efforts to do it right. Then you can actually enjoy using it and have success. Best of luck.