We also use amazon, but have also used Marks & Spencers www.marksandspencer.com they do nice flowers and will deliver anywhere in the UK. If you wanted to do perfume or cosmetics try Boots... www.boots.com
If you were feeling really flash and werent worried about spending a bit of cash - try http://www.harveynichols.com/hampers/ProductDisplay.aspx?catID=3
We used to use Amazon the other way around - when we were in the UK and wanted to send presents here....worked really well!
Happy Shopping!