1. Glass HousesWaterstone's have an offer on at the moment - all the above are at half price and UK postage is free.
2. The Dead Girls' Dance
3. Midnight Alley
4. Feast of Fools
5. Lord of Misrule (UK: July 09)
So far, I own nos 1 & 3 and am likely to fill in the gaps though I really should perhaps try one first!
The sixth book, Carpe Corpus, is recently available in US paperback but the UK publication date is 12 October.
Rachel Caine's website is here.