I have a really nice stereo and entertainment systems. What are the options? Electrical converters? Sell and purchase new?

Yes, that’s always the dilemma when moving back from a foreign country. From the US/Canada, it’s either a voltage/plug adapter, or sell and buy everything again in UK. Selling your equipment before returning might help fund repurchase and save on moving costs of those items. Also keep in mind that television systems are different.