My cafe lock solution (which I'd also use for lightweight touring) is a kryptonite evolution LITE mini-6 and a kryptoflex cable. The mini-d is ridiculously light, but still Sold secure Bicycle Silver (mine tips the scale at 733 grams).
I usually use the mini-d through the seatstays and rear wheel, and as the lock through the kryptoflex which goes round something solid. With sheffield stands, I can get the mini-d itself round the frame and stand.
When I bought it, there were no UK outlets, and I had to get it form the continent (via Amazon). It looks like it's been available at Evans since then, but they are sold out (and presumably not getting it back since the price on the sold out page says "clearance")
For heavier weight camping my trusty Abus chain comes along instead (~2.5kg?).