Daniel,
I also shoot mostly landscape but with Nikon gear that is similar to your Canon equipment weightwise.
For the past six months I've been using a Giottos GB3150 legset and Kirk BH3 head. The BH3 came with an Arca-Swiss type clamp (which I use) and generic plate (which I don't care for). Total cost was about $400USD. Even factoring in the L bracket and lens plate, you're not going to go much, if at all, over budget with this combination.
The Kirk BH3 handles the load very well and doesn't slip. While the Giottos legset isn't up to Gitzo in build quality, it's not at all bad. Without extending the center column, my viewfinder is right at eyelevel (I'm 5' 9") and the bottom leg sections still have about 4 inches left "unused".
Within a few years, I may have to replace the Giottos legs with a set of Gitzos but, until then, the Giottos is serving the purpose and only cost me $135USD from B&H. At that price, I will be happy to upgrade it when needed and/or budget allows.