Hi JMB,
I've got a pair of 15X70 binocs and admittedly they get a bit tiresome after 5mins of holding up at anything over 60degress.. I then bought a cheap camera tripod from ebay which turned out to be a fizzer - too light, the height was not what was specified, shakey when fully extended (1.5metres). That height is useless to me since I'm 6feet !
Unfortunately to buy a good quality tripod or binoc mount is not cheap. But as a thought I was browsing thru a JayCar catalogue and came across a pair of Heavy duty Speaker Tripod stands. From the specs, they will extend up to 2m and can told up to 45kilos!
To get alt-az movement you then need to take off the head off a camera tripod and somehow work out a way of mounting them onto the speaker tripod - it might just need some brackets/bolts. If that works, all up you could be setup for around $130 and have a very solid tripod.
btw: I haven't persued this as yet, I've resided to just scanning the skies quickly and if I want to look at something for an extended period of time I whipout the old bean bag and contort myself accordingly !