Where should I Buy seeds?

for my next grow session, I am looking to acquire two particular strains of cannabis, and possibly end up crossing the two. I am looking for, Rainbow Kush, and G13 seeds. If anyone has an idea to where I can purchase each of these strains I'd be extremely appreciative!

Here is a good place to start.

http://rollitup.org/f/seedbank-reviews.88/

Thedankteam, attitude, herbies, singleseedcenter. That's not in any kind of order

whenever I'm searching for a particular bean
I google it and look for a familiar face in seed banks exactly those mentioned above ^^^^^^^
and now I found a bunch more stateside on the advertiser threads.