Upload & Sell: On
All that Rob says is true about the 24 TS-E II, but the original is quite impressive when matched with LR4 (pick the profile for the 24/1.4 original, plus use the CA correction and you'll have a great image!). That's a great starter lens for architecture -- I'd rather have that than the new Samyang with its electronic aperture control and exif info.
You won't really need filters indoors (and can get by without them mostly outdoors), so you might try the Tokina 16-28/2.8 so many talk about. From what I've seen on forums, it makes better images than the 17-40/4. Personally, I like the 16-35L II, but that could be gotten later on.
I successfully used the original 24 TS-E and 17-35/2.8L for about 10 or 12 years, only upgrading a few years ago to the new 24 TS-E and 16-35L II. (that 17-35 isn't a bad starter lens either!)
Good luck on your quest.