http://www.pprune.org/forums/showthread.php?t=203488
This is the link to the EFLGW / LGW Fleet thread.
Uniform stores is in a bit of an obscure place, and the people who work there are NOT BA staff so I do appologise in advance for any attitude you may recieve.
You may commute from Spain, but you may find it tough on just shorthaul until October. As for the tax situation it would seem that the loophole is being closed in the not too distant future so you WIll have to pay tax in either Spain or the UK