phones for you was the best i found for the 8520, they offered me the phone for free, 400mins, unlimited internet (all the features work, like push email etc) and texts on orange for £25ppm. Also, they gave me £30 for my old phone, and gave me cash to pay off the last 2 months of my o2 contract, and a manager gave me a tenner for coming back the same day
went to the orange shop and was amazed by the 2 people I showed the quote; one looked at it, laughed and walked off, then another said 'we can do the deal, but not the cash back for the phone and contract' and didnt even attempt to sell me anything better. oh well.
anyway, go to the highstreet, get some quotes, they're all trying to beat eachother for your business so play them off one and other and you're sure to get a good deal somewhere.
good luck