>Anywhere in the UK I can purchase the latest firmware
>upgrade for my Picstart Plus?

You can do it through the Microchip Buy Online. That is the way mine
eventually got to me, after queries were made through the Memec folks that
Dominic put me on to. If you click on the UK flag the prices at Micochip Buy
Online come up in GBP.

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics