You'll get as many suggestions as there are brands of strings. Personally, I like D'adarrio Chromes because I can get a smooth flatwoundish tone, or a bright punchy, almost round wound tone, all from the same strings.
Since you're in the UK, I'm not sure about availability or prices, but Chromes are about $40 here.
The thing to remember with any flats is to give them time to settle in tone-wise before you decide. Depending on how much you play, it could take several weeks or more to break them in.
Good luck in your quest, B.