This thread's a bit old, but I thought I'd revive it in case MDX or anyone else is still interested. I'm currently looking for a Buffy box set myself, and I've been researching the subject.
There have been three Region 2 Buffy box sets (all 7 seasons): the limited edition red box, the limited edition black box, and a new set due out on Oct 31st which I assume will not be a limited edition, though I'm not sure.
The limited editions are no longer available from major suppliers, though you can still find them new or used in various places around the internet. The one you describe from Choices Direct sounds like the black limited edition. They had none of those left when I looked yesterday.
The new edition is being sold at a much lower price than was originally charged for the limited editions. (There are also cheaper editions of the individual seasons coming out.) Amazon is taking pre-orders at £135, inc delivery. The lowest I've seen is £133.
Many suppliers are illustrating this set with a picture of the limited edition red box, which was very compact and opened at the front (see
http://www.whedon.info/article.php3?id_article=7408). But I think the picture at Play.com is the correct one for the new edition. It looks as if it opens at the top. I assume that individual season folders will slide in vertically. But just what form those folders will take is unclear. They may be the new edition single-season folders, but I don't know what those are like.
If you can play region 1 DVDs, you should also consider the R1 Buffy set "The Chosen Collection", which is due out in mid-November. (The USA has not had a box set yet.) Amazon.com is taking pre-orders for a ridiculously low $130!!! Even with delivery and customs duty that should come in at only £100. Plus it contains an extra 40th DVD, with new extra features. But bear in mind that the R1 DVDs are all in 4:3 ratio, whereas the R2 are widescreen from season 4 on. The show was framed for 4:3 TV and Joss Whedon insists that that's how it should be watched. But I must admit I like to see it in widescreen. There are also some other less significant differences between the R1 and R2.
I've put in a bid for a used red box set on eBay. But I doubt I'll get it for the amount I'm willing to pay, in which case I'll probably buy one of the new sets. But I haven't yet made up my mind whether to get R1 or R2.
There's also an R2 Angel box set due out on Oct 31st. I believe this will be the first Angel box set released and it's a limited edition. From the outside it looks like it's designed to match the Buffy red limited edition set. I'm toying with the idea of buying Angel too. I'm not so keen on Angel as Buffy, but I wouldn't mind watching the whole series through once more (and I haven't yet seen season 5 at all).