One of the problems I heard about UK (and probably EU) customers is that of duty and insurance problems with goods coming from the US. I already reported on the duty problems you might run into - now I want to talk about possible insurance problems.
I sent this question (unanswered for the last 2 days) to LensCatalogue: "Do your prices include VAT at 17.5%? Does your invoice separate the 17.5% so customers can then reclaim from their insurance companies? Does your invoice also include the company name, company number, registered office, and VAT number?".
I sent the same question to CoastalContacts.co.uk. Coastal DOES ship from outside the EU, but from what they've explained to me about their operation, I am guessing that they do their invoices correctly. I greatly doubt that the other non-EU suppliers do this, but I wait for a reply from LensCatalogue to see what they have to say.
I am not a lawyer nor an expert in insurance claims - I'm only going on stories I heard where I did not investigate thoroughly. Right now, I just want to see what the companies have to say. However, before buying from the US, you should make sure that you are covered.