I have used Interparcel for sending various things, including bikes, bits of car and computer equipment.
They are usually good value as they are a broker, and you can choose the end carrier, cover and delivery type - typically cheaper than going direct.
In the only instance that something I sent failed to arrive, they were very helpful in sorting out the problem. I found a replacement item and said 'get it from there' and they did the legwork.
Also, they take paypal.