Hi Roy
As you may have been told you can buy pretty much everything you need here but it can be expensive.
The big supermarkets sell everything you need to start up including bedding and kitchenware although you cant beat a few home comforts. (We have a big stash of Yorkshire Tea bags too).
Shopping is quite a familiar experience with BHS Marks and Spencers and Debenhams all available in Doha plus loads of other High street stores.
My advice would be bring a few things you cant live without and essentials for the first few days.
P.S
Long shorts are fine for the airport