I hear what you're saying about being paranoid, but you don't necessarily need to limit yourself to bag seed on account of that.
http://www.weedportal.com/ is the anonymous mail-order site for Nirvana seeds. Prints out a form and gives you an mailing address. $1 for an airmail stamp, $25-40 for the seeds, and your golden. Of course, mailing cash is an act of faith (and you need to be careful to hide it in camoflage paper inside the envelop so it don't get stolen), but from personal experience, it works! Got my Wonder Woman seeds in 3 weeks and change, and they're growing awesome. I've done bagseed grows before, but I will never do one again.