Well if you plan to immigrate , go for US. Because the visa system is much more complicated in UK .Also you'd need hell load of pounds to start a fresh living in UK. Start with 2500$ a month in US. I've added an extra margin to your budget since you need to look for affordable accommodation and a decent salary job.
why someone need to immigrate when he can earn online, i think immigrating is a thing of the past
tere are plenty of job online, and some pay in bitcoin, you can earn really well
and unless you live alone immigrating is not easy to do with a family, it will cost you plenty of money
to stabilize yourself in a new area