Why so hurry? Even if not in stock, it's possible to wait one week, as I am. Ask in shop I've linked, how much waiting.
100 pound plus shipping is more expensive then 129 euro.
Most of my purchases for Lee products came from Great Britain, only a few from the USA. I couldn't find anybody who carried it all, so had to piece meal my Lee system. I have colored filters, too, but only really use the "real blue" resin slide to pop the sky. Otherwise it's ND and Polarizer.