I don't know how high you would like it, what about Evergreen Andersonii variegata Hebe or a Red Robin.

How about a dwarf conifer in the middle surrounded by heathers. You will need to keep the heathers pruned unless you want them to get pushy. Or you could have a tall central shrub and plants trailing down the sides of the barrel. I'd also put in some dwarf bulbs for spring colour.

thanks so much for the advice , im kind of new to this and welcome any advice - i will be going to the garden centre today to look at the options you have suggested , thanks again ( i will keep you posted with what i do )

Will look forward to a photo of your planted up wisky barrels.

will post some pics as soon as there done

Thank you Ross I will look forward to seeing the display.