Hey man you can try
www.chumajek.com they send to USA also they sell single seeds from a lot of seedbanks. Talk with " Pupix " is the owner of the company, nice boy ! i bought in this site by 3 o 4 times and never had problems.
Also you can find a lot of seedbanks that sell their genetics in 1 seeds pack, it´s very interesting because you will get the seed in the original packet... for example:
1 seeds ( original packet Seedbaks )
- Advaced Seeds
- Dinafem
- Pyramid
2 seeds
- Dr. Underground ( man i grew Melon Gum and she is a f**** sweet monster heheheh, really nice )
3 seeds
- Sweet Seeds
- Advanced
- Dinafem
- Pyramid
- Paradise Seeds
...
Peace bro !