Moving to Israel from the UK
The United Kingdom is a cold and rainy place and people are not warm blooded like in the Middle East. Moving to Israel from the United Kingdom can be a tempting option if you're thinking about a new home. There are however some things to consider well before making the big step of actually moving to Israel from the UK.
It can be a good idea to limit your stay in Israel to a couple of months. As a UK citizen you don't need a visa up to 3 months. It's good to go on a (flexible) return ticket, as personnel at Ben Gurion will enquire about your plans and return flight. It's usually easy to extend the 3 months visa. Some people try border hopping to Jordan instead, e.g. with a 2 day trip to Petra, but this could be risky as you might be only given a short visa when coming back to Israel.
Flights to israel from the UK
There are many flights to Israel from London. If you insist on kosher food you're probably best of with El Al. The profiling at the airport can be a bit annoying though. El Al security is tough already at the airport in London, even with Jewish Israeli citizens, almost as if the Israeli military itself is present.
Immigration to Israel
Basically there are two options. If you are Jewish, married to a Jew or if your father or grandfather was Jewish you can make Aliyah, this makes immigration to Israel a snap. If you don't fall under the previous category things will be a bit more complicated, especially if you have a Muslim or Arabic background.