I dont buy much camera gear
but here is what I find places where I have bought camera equipment.
Grays of Westminster:- Nikon specialists with almost everything in stock. I spend much time at the beginning of this year working in Central London so I took the opportunity to collect items to avoid carrier related issues. Grays always wrapped items to make them inconspicuous for me to take into meetings etc. 75% of my gear is purchased in this way. I have been successful in haggling but dont be surprised if they take offence.
LCE:- Lincoln branch managed to supply D2X after one week of being launched. LCE had D2X on the shelves before most other Nikon dealers.
Warhouse Express:- Everything I have ordered was in stock and shipped as promised.
Mifsuds:- Slight delay after promised shipping date, telephone call to resolve. This was in between Christmas and new year so no real complaint.
Jacobs Photo:- Derby branch friendly and knowledgeable very happy to help.
Dabs (online):- Purchased compact flash cards and HDD's. One delivery went missing on the post but was replaced swiftly and without hassle.
I have never had real problems so I recommend all of these sources equally.