Hi Steve, sorry I've not got back to you since you PMed me :oops:
The off-the-shelf CV boots that are for sale at most car bits shops are rubbish.
For some reason the compounds they use now use on rubber parts perish very quickly and in no time at all you'll be replacing them again. I decided to look for a better alternative when a replacement I had on the shelf was starting to split before it had even got out of the box!
The ones to go for are made from Neoprene. They are actually designed to be fitted (using a fitting tool) without the need to remove the CV joints from the drive shaft, but can be used like a standard rubber CV boot - which requires the drive shaft is separated from the CV Joint. They are more expensive but last considerably longer.
You need to ask for 'extra stretchy CV boots'. They are universal fit and are cut down to size.
The last ones I got were made by a company called
Bailcast - Uniboot Part Number CV96.
I think they were a little bit over size as I had to cut them down quite a lot. I think their
Duraboot DBC800 would be a better fit.
http://www.bailcast.com but available from most motor factors, online or eBay.
They also do extra stretchy steering rack gaiters designed to be fitted without the need to remove the track rod ends.