Not sure if it's all that easy to get the brand over in the UK but I've had great success with my Spark SPII by Sea to Summit. With a thermal liner I slept comfortably down to about -2, and with my silk liner it was fine down to 5. Best part is it weighs shit all and packs down to the size of a large grapefruit. I'm also a big fan of grapefruit as a vitamin packed breakfast food, or for alleviating the common cold.
Not sure if it's all that easy to get the brand over in the UK but I've had great success with my Spark SPII by Sea to Summit. With a thermal liner I slept comfortably down to about -2, and with my silk liner it was fine down to 5. Best part is it weighs shit all and packs down to the size of a large grapefruit. I'm also a big fan of grapefruit as a vitamin packed breakfast food, or for alleviating the common cold.