2 of the mounting thingys from deal extreme, seconds to put on and remove. Helmet doesn't feel badly weighted and when sat on head torch is at a good angle IMO.
Ive got the Camelbak Octane 8+ and think it's great. 2L bladder and opens up to take as much gear as I need for a full day out(seems to hold more than it states). Then zips and compresses up to quite a small short blast pack. Seems tough and very well made and sits very securely when on. Go Outdoors had them for £44 when I was last in.
Ive got 2010 Float RLC QR15 with the FIT damping. They feel superb over small bumps, and move through travel very well. Im coming from QR to 15mm so feel plenty stiff.