I was going to get some from Mr Gaiter, but my girlfriend convinced me that the gaiters from Redline Goods looked better (http://www.redlinegoods.com/). After some initial troubles of not thinking that the gaiter would fit around the metal base of the gearstick, I had a back and forth with the guy and he was very helpful, always answering my mails promptly and even asking me to trace the surround so he could make sure that it was correct.
In the end, out of sheer laziness (and because I'm a stubborn git), I managed to get the gaiter to fit. It seems it was just really tight as it was new leather. The handbrake gaiter fit perfectly. I'm really happy with the quality of them. they were a little more expensive than Mr Gaiter etc, but I feel that I made the right choice.
I looked around on the net before ordering and found a code that automatically gave 10% discount, so that helped to reduce the price a little too.
I should mention that the gaiters I got were for the R32 GT-R.