Its quite hard to say. What are you expecting from your first grow - yield, potency/quality, ease of growing, time it takes?

Like LIP said, if outdoors go for Durban Poison. It grows massive, but your looking at at least 4 ounces per plant if taken care of properly - someone on www.everyonedoesit.com grew 2 DP's outdoors (this is in England aswell), planted in May and harvested in September, and they got 7 ounces per plant! Thats a helluva lot of Herb from one plant!
Or, be like me and grow a few Lowryders. Theyre extremely hardy, grow short and bushy, hardly require any attention and you dont need to fanny around with changing the light cycles for vegging and flowering. Just leave the light on for 18 hours a day (18/6 means 18 hours on, 6 hours off) and 2 months later youll have a little bud-bush. Just do a search on google images for Lowryder, youll see what I mean.
The problem with Lowryders are that you really dont get a lot of bud from them - grown under a couple of CFLs (compact flourescents) youll get 10g max. Grown under a 400/600w HPS, youll probably be looking at close to an ounce per plant. Theyre more for learning the basics than anything else, although it is a fun little plant - plus you can only smell them if you shove your nose right up to them and rub the buds, so it scores brownie points in the stealth area.
Oh, as for getting seeds in the US - a lot of places are being pretty strict about sending seeds to the US after whats been happening with Marc Emery/the B.C Three. Cut a long story short, he sent shitloads of seeds to the US from Canada, and now the US wants his balls for breakfast.