Boycott?

From, the CIA world factbook, a list of Israel's main exports:

Exports - commodities:
machinery and equipment, software, cut diamonds, agricultural products, chemicals, textiles and apparel.
So, if you want to boycott Israeli goods, check your fruit and veg and flowers at your supermarket; look at the labels in your clothing; find out where your company gets its software from.
However, direct imports to the UK are minimal, so the effect would not be hugely significant, and even if it were so, its direct impact would certainly be upon the poorest people in the country, rather than the warmongers.
As for direct boycotts of companies that support Hezbollah, I haven't the foggiest.