I shipped a £2000 bass out to Basschatter Nobody's Perfect in Finland, nearly two years ago now. I shipped using the DHL road service which took three to 4 days to get there.
I arranged insurance separately via broker who used Norwich Union (Aviva now i think?) Was very easy to arrange the cover, a quick phone call and he mailed me the form to sign and fax back to him. The Insurance cost £55 in total and shipping was about £30, as I recall. Interparcel would be a good place to sort the courier - I used ParcelForce at the time
If your're interested I can dig out the details for the broker etc
Hope that helps
P