Hiya,
That bike will be fine! Unless you're going waaaay off the beaten track I think the hydraulic brakes will be okay. I changed to cable-operated disks for my trip through the Himalayas, but in France & Spain you'll never be too far from a bike shop which will be able to fix any disasters. As has been said above, it can be a bit of a faff to fit a rear rack when disks are installed, but it's perfectly do-able; I'd definitely get a 'proper' rack though, rather than a seatpost job. For the front, I heartily recommend a Tubus Swing, which mounts your bags above the active part of the suspension, isolating them from vibration and making a very smooth ride. If you can be bothered, there's a picture of the bike I took to India near the bottom of this page:
India 2008
As long as the components you have are in good shape and you find your saddle comfy for full-day use, then you have nothing to worry about and no need to spend any money on upgrades. You'll have a blast! Enjoy!