After the price reductions of SanDisk and Lexar memory cards in the US, SanDisk has repositioned their SD range in the UK (expect Lexar to follow suit shortly). The fastest currently available are the 95MB/s* (633x speed rated equivalent) cards under the Extreme Pro branding (note there are some slower variants around, but this maybe older stock.) These cards are UHS-1 (class 1) UDMA-6 compatible but use a different controller - the same as the CF Exteme Pro series. Previously available at £79, the 16GB card, for instance, can now be had from Amazon UK at just £43.50.
Wex are retailing the 16GB Extreme Pro card at £59
Jessops are still retailing the same card at £71.96 (was £90).