no, you dont need to size down. It's a wide last but not long, so good for wider feet.
I didnt know Tom LS stocks them, have never seen them in any stores myself. But the UK sites they are readily avail at are all great, super fast shipping and they deduct VAT so with the current exchange rate they end up being under $400 for most pairs.
Definitely take a look at Pediwear, they ship Trickers for FREE, deduct VAT, threw in a pair of awesome shoe trees and polish. AND, when you buy your first pair from them you automatically get put on their "Trickers Club" so in the future any website orders you get all that PLUS an additional 5% off. killer deal once you know exactly what size works for you which isnt hard because they are very TTS, and if you dont know your "true size" I think the best method is to try on a pair of Allen Edmonds (which fit very true ime), find the size that fits best (in whole sizes) then subtract 1 for the UK equivalent.