Looking for one for TD's. Let me know if you have one that you would like to move on... If they come in sizes (no idea if they do or not), I am 6ft and of reasonably slim build, normally fitting into Medium sized t-shirts and that sort of thing. Cheers.
I've got a Knox, it's very comfy too. But as has been mentioned you need to try on, the shop measured me in fact to ensure a good fit
I have got one of these to try out at donny next week! http://www.forcefieldbodyarmour.com/product/airo-vest/2427 Most manufacturers have a sizing guide that shows you where you need to measure to get your size.
Look around and you'll see most track dayers are using Alpinestars, Dianese, Forcefield or Knox. You'll probably need a Large due to your height, but check first as mentioned and consider squeezing in a chest protector too.
Thanks for the advice and recommendations all. I'll get down to a few dealers and try a few on before plumping for one in particular - I hadn't thought that they were a bit like helmets in that different makes/models fit different people differently...