In reply to Philchris:
You need to look at https://global.llbean.com/ they export to the UK and the price includes delivery, import duty.
They do TALL sizes for almost everything. Checkout their silk base layer. Silk is really warm for the wight and not sweaty.
I am 6' 6" and ski and walk in their kit, though just watch out for taped seams on waterproof stuff as in the UK its standard, but in the US not necessarily so!