The thing to watch when arranging a personal import is VAT and duties - any goods over £135 iirc is liable to duty, and anything over £35 liable to VAT...and they also charge these on the cost of delivery too.
This may seem reasonable, until someone allocates the wrong duty band/product type which attracts a different duty band (this is more likely where the shipper does not know the international customs commodities codes and leaves it to the carrier to complete the paperwork). You cannot appeal and you do not receive the goods until the duty and VAT are paid.
Remember doing business here in the UK is vastly more expensive than in the USA and we have to recoup those costs somewhere...and when somebody needs advice they call us, not the USA, or spare parts, or HSE advice, or training, or spare parts delivered tomorrow because otherwise they lose money through not being on site...
Also, if you waited six weeks add up how much you could have earned on stilts in that time. Many customers tell us they pay for themselves on one job, so the cost is readily covered by the convenience of getting the goods when you want them.