Check out the Sweet Seeds range and try Pev Grow, they ship stateside and accept credit/debit cards.
Look for a strain with a high percentage of Sativa genes, this will give a more uplifting effect and remember to not pick too late, about 90-95% brown pistils will give you a more euphoric effect than late picked flowers with 100% brown pistils, which will give a more sedative effect.
Two such strains are Black Jack and Jack 47, both are powerful and a fun type of high, making you smile uncontrollably.
Otherwise look for strains with Thai genetics - Thais are famous for giggly dope.
Hope this helps,............
Organoman.