you should not pay import for items from chinavasion, you can chat freely with there online support about which plug the item has.
most of there items, you can choose uk eu usa etc.
you should however check with uk customs with import duty to be 100% sure.
A simple email to them will surfice.
although a trusted website, be careful what you buy as a large percentage is garbage.
do not believe the reviews etc as these can very easily be entered by the webmaster.
from experience the cell phones are generally ok not great just ok.
what exactly are you looking to sell?