I'm not talking about making a fast buck here
Which a retail investor should never try to do anyway. The system is completely rigged towards the market makers, and large institutions when it comes to making a fast buck. Normies that make a quick buck are lucky exceptions.
there's also a potential burglary risk.
Gold is the worst for that. A compact store of wealth, that is completely untraceable and for all intents and purposes practically irrecoverable.
I dislike currency trading
Another good thing. Avoid all the "Forex" sites like the plague. These are essentially criminal operations, parting good people with their money. Guys with PhDs that work at hedge funds, haven't a clue about where currencies will move - but just make educated guesses. Your chances against them are hopeless.
Of all things mentioned, bonds are probably the safest bet. Gilts are kind of a complicated story, I would rather look at US Treasuries.
That being said, if you did well on your real estate investments, why not just continue with that? If you don't have the means at this moment to buy something interesting outright, you could still invest into REITs. Real estate investment trusts own income producing properties, and as a shareholder you're paid your little share of the rent, as well as earn from the appreciation of the underlying asset. But be careful with REITs - study them carefully, and if unsure ask me - I'll tell you if it's trash.