Swoop - a move to Ireland would be better than moving to Britain. No snakes at all in Ireland. I have never seen an adder/viper in England. The only snake I've seen out of captivity in England was a dead grass snake. Went to Blackpool fair once, where you could have your picture taken holding a snake. My ex-wife was up for it - had it twice coiled round her neck, and held its head. I wouldn't touch the damn thing!
But I am fascinated by snakes. The American ones are nothing much. Real snakes live in Australia, which has the ten most poisonous snakes in the world. These include the death adder (7), a sea snake (5 or 6), the Taipan (3 - lives amongst sugar cane and has a horrible bite with "machine gun" jaws"), the Brown snake (2 - the most dangerous snake because it lives in suburbs near people, and is not known to suffer fools gladly) and the most poisonous snake of all - the Fierce Snake - lives in the wilds of Northern Territory.
Most snakes will not engage a human. They are looking for small prey for food, and are not interested in us. Most would therefore avoid us. One exception to this is the African snake, the Black Mamba. That thing will stand 4 feet high, and will give chase. It uses a side to side sweeping motion to propel itself and can reach 17mph.