You need to work out your costs (supplier cost+shipping+duty+VAT) and also how much stock you need to hold between deliveries. Shipping by air is the quickest (about a week) but is also expensive, by sea takes about 6wks so you might want to carry 2 months of stock to cover any delays.
Have a look here
http://ec.europa.eu/taxation_customs/dds/cgi-bin/tarquer?Lang=EN
There is a better site but it's down just now, google Tarrif codes and go to the business link site and search on product description.
Also you may be charged on volumetric factor rather than weight