To build one of these kits in the UK you would need to get the design approved by the PFA (I don't think this one has been, yet, you could check on the PFA website). I'm told it can be a lengthy and quite tedious process, even for designs that are backed by a lot of engineering knowledge and data.
Or you could move here to homebuilder's paradise and just build it.
There are a number of Spitfire replicas around, you can see some at
www.spitfire.org
I know there are a couple of 100% scale wooden ones under construction here in the States with Griffon engines. Also Clive du Cros made a nice 100% scale replica of the Spitfire prototype K5054 a few years back (& published a book about it) although the airplane had an unfortunate flying career.
For me the nicest looking Spitfire replica is the 80% Canadian one built by Bob Cutting & Terry Wilshire. I believe the latter is working on a kit & set of plans for it.