Moving a small amount of furniture and person items from USA to UK

My fiance and I are due to be married in just under three weeks whereupon she will be moving to the UK to live with me. She doesn't have a lot of things that she wants to bring with her but more than can be packed into a suitcase and more than can be reasonably transported by air freight without it being cost prohibitive.

We have decided to try shipping her things via boat but are having a few problems finding a suitable company. Basically we have an old writing desk and some other personal effects which should fit comfortably into a 60(ish) square ft container however the only company we can find providing such a service only does shipping of that size in cardboard containers which aren't suitable for heavy furniture.

Does anybody here have any experience with shipping things internationally and if so can you recommend any decent companies?

Thanks in advance.