the Manfrotto 055PRO B will probably suit your needs. A few members here have them, and seem pleased. I've got one and love it (with a manfrotto 322RC2 head). You may want a different head though (the Benro ball heads will work fine) as the 222/322 isn't to everyone's taste.
Teds usually keep stock on hand of the 055PRO and it's usually around $280 or so. Vanbar.com.au have it for around $290 shipped.
Killakoala (Steve) has a decent review here:
http://www.dslrusers.net/viewtopic.php?t=1761
It aint as flash as the Gitzo's, but then again it doesn't cost as nearly much.
As for simplicity and sturdyness - the 055 is great value for money. Simple but tough leg clamps, can get very close to the ground, decent sturdyness for the weight.
If you're after outright sturdyness, look at something like the 058 PRO. It's definitely heavy for field use though. If you're doing a lot of nature work, the extra features of the 055NAT might be handy.
If you're after Carbon Fibre, the Benro C227/327 will compare favourably price wise against the Manfrotto Magfibre range.
Cenre Columns mounted horizontally - the PRO designation on the Manfrotto range denotes this feature - available in the 190/055 and Magfibre range.
Other thing I like - if something goes wrong / need a spare part (they are tough, but) it's easy to get stock in at most camera stores anywhere.
Useful link:
http://ilikecameras.com/equipment/going-steady/
Good luck!