Where should I put £40,000 in cash I won't need for two years?

This is quite straightforward given your timeframe. With two years, I wouldn't go near shares — keep it in cash. Think about tax. Investigate shorter-term gilts if you are near your limits for capital gains tax allowances, especially if you are a higher rate taxpayer

. Use your cash ISA allowance of £20,000 this tax year, and consider the best fixed-rate accounts with the rest — either a one or two-year fix. But again, remember to work out what the tax position would be for you and compare this to your position if you bought a gilt (or government bond). Hargreaves Lansdown has some helpful information on gilts.