best shops for bedding/linens

Hi, what are the list of the best places for bedding. I am looking for preferably egypitian cotton sheets 600 threatcount or more, sets, ( pillow cases, flat sheet and fitted sheet) or all of these in separate sets.

I have tried the following:

1) Homecentre-- they sell very few flat sheets and when they tried to pair flat sheets of similar colors the flat sheets were less threat count and one was even poly-cotton.

2) The one-- teeny selction, nothing over 400 TC

3) West Elm-- Teeny selection nothing over 400 TC

4) Engliish home - Teeny selction -- nothing over 300 TC

5) Pan Emirates -- doesn't sell sheets

6) Ikea,-- their sheets are sandpaper.

7) Marks and Spencer-- nothing over 300 TC, teeny selection

8) Debenhams. Didn't see any sheets.