I've used http://www.profabrics.co.uk and their 1000D cordura for the outer, and lightweight ripstop for liners. They've got pretty much everything you'll need!
Is that 1000D the norm? 380gsm seems like it would make a heavy bag! I'm going for more of a carry-as-little-as-possible-to-preserve-the-spritely-road-hugging-joy-of-italo-steel than a stay-attached-while-I-send-it-down-a-welsh-hillside.
I've used http://www.profabrics.co.uk and their 1000D cordura for the outer, and lightweight ripstop for liners. They've got pretty much everything you'll need!