Will US wii consoles work in the UK and are UK games compatible?

Yes and no....

The console will work, but you'll need a TV capable of displaying NTSC (UK TVs are PAL), you'll also need to either replace the power supply or get a step down transformer.

Nintendo has region locked the games for the Wii, you can only play UK games on a UK console. However this is not necessarily a bad thing as by ordering online from US sites you can still get new release games fairly easily, although the exchange rate has eaten into the savings somewhat.

One major downside is that you won't be able to access the UK online service with a US console, only the US service.