I got a Velbon tripod from Jessops a few years back (quite a few, actually). It cost about £120, has square-section legs and a rather spiffy fluid head.
Have a gander at
http://www.jessops.com, product VELDV7000 (approx £80) to get an idea... Not pocket money, but well worth it IMHO - the cheaper models seem to be really for stills cameras. Would £20 get you a good fluid head thingy?
The tripod I used is a monster that pops up to around 7' tall, quick release mouting plate to quickly dismantle the thing without faffing around, and rock solid, with built-in spirit-levels. I think they've changed the model number since the I bought mine, and there's no doubt other brands which would do, but if you want stability you have to pay a bit more.
I wouldn't describe it as small, light and compact at 3kg-ish, but I managed to lug it up a few steep hills without a hernia. A good carry-case with a shoulder strap helps too. The improvement in quality could be worth a little sweat.
Alternatively, if you don't really need 100% stable shots, a monopod might help. Always thought they looked a bit daft though!
Mike