Can I use US dropshippers if I live in the UK ?
Yep, you have the choice of using Dropshippers located in the UK itself or you can use international Dropshippers who ship internationally. Of course you also have the choice of dropshipping in countries outside of the UK as well if you want.
I don't see the reason why not, unless the dropshipper does not ship to the UK. We do have several dropshippers that will readily dropship internationally.
If you need help with anything else, please feel free to let us know.