Thanks for the response, unfortunately I do not have access to a 4-poster lift.
Looked further into the cost supply only is £555 supply and fit is £603, so the the extra 50 quid seems easier for them to do it. Would have been nice to try and cut the cost of the tubes themselves, have seen non OEM ones on ebay for £200-£250, but not sure how good they are, but a good saving.
Any comments much appreciated.