south, have you seen this? http://www.bbc.co.uk/bbcthree/item/92a3cfc5-7078-4c21-b7e5-cb3b23b41ab7 I stumbled across it last night, and thought it was really lovely. It's big news, so take your time letting it sink in and don't worry if you feel angry and sad, get as much support as you can. CF is different obviously, but if you want to chat about managing with kids who have lifelong health issues please do shout. You'll find lots of DS specific support out there too I'm sure.
In terms of essentials first, I wouldn't bother with a changing table personally, or a nursing chair, but it's up to you what you want! Do make sure you get a changing mat with raised sides though so you can use it on a normal table, bed etc without baby rolling off. I'd also second nipple guards and muslins as vital! Loads of nappies too!
london, we'd been wondering about this too but thankfully DPil came to the rescue and said they'd drop everything for us whenever it happens. They're about an hour away, so that should work ok. My main concern is DTs being well at the time new LO arrives, but only time will tell with that.
turnips, do bear in mind they call back to check regularly so try not to panic. When are you going back?