Let him come to you. Don't force the issue, and personally, I wouldn't even try petting him until he initiates it by rubbing against you or giving you head butts. You can extend a pinky finger for him to sniff as a greeting, and offer him tasty treats as a reward for interacting with you. Have you tried gentle play therapy? Being a kitten, he should find furry or feathery wand toys or fake mice irresistible and they might help draw him out of his shell (provided you don't make sudden or threatening movements in the process).
There's some good advice on how best to deal with fearful cats by feline behaviourist Pam Johnson-Bennett at this link: http://www.catbehaviorassociates.com...a-fearful-cat/
How old was Parker when you got him? I'm wondering if perhaps he wasn't socialized enough by the breeder, although maybe the trauma of the plane trip has also had an affect.