I would suggest strongly considering the Tokina 11-16mm f/2.8 instead of the Canon 10-22 f/3.5-4.5 USM. They are about the same price & image quality. The Canon has a bit more range on both ends, but most people tend to shoot their UWA at the widest end, at least the majority of the time, and so there is not much difference in that regard. However, the Tokina has great build quality (not weather-sealed, though neither is the Canon), and is also a 'faster' lens across its entire range, which may be enough to make a difference in low light situations e.g. sunsets & sunrises for landscapes, indoors without a flash/weak built-in flash etc. The Tokina 11-16mm f/2.8 also makes a great video lens, and therefore ideally suited to the Canon 60D you plan to get.
Both the Canon 17-55 f/2.8 and Canon 15-85 f/3.5-5.6 have good reputations. Canon 17-55 is better suited for indoors/low light, Canon 15-85 is better suited for outdoors in better light conditions (more range, where light capturing abilities not as critical). Also worth noting, the 15-85 is about 2/3rds the cost of the 17-55. I would suggest trying to buy a better quality general purpose lens than the kit lens, rather than renting that one, if possible, since that is the lens most likely to be on your camera, both during the trip & after, so that is the lens the most photos are likely to be taken with.
One other option to consider is a superzoom like the Tamron 18-270mm f/3.5-6.3 Di II VC PZD AF. Any lens that has more than about a 5x zoom factor tends to give up some image quality, but there is no denying the convenience of a superzoom i.e. less lens changing / quick & easy adjustment to a wide range of focal lengths. And being able to capture a photo in lesser quality is better than not being able to capture a photo at all, in those situations where you don't have the right lens (either on you, or on the camera) at the time. The image quality almost definitely won't be as good as one of the Canon general purpose lenses listed above, but will likely be better than the 18-55 kit lens, while also gaining you the ability to capture some photos at the long end that would otherwise not have been possible.
Lastly, I suggest at least purchasing the Canon 50mm f/1.8, given how cheap it is. Yes, it's kind of a bit narrow for many purposes on a crop sensor, but it will give you some low light capability, and could be a 'foot zoom' backup for your general purpose lens, in the unlikely event that lens has a problem.
So another take on the suggested lenses could be:
Tokina 11-16mm f/2.8
Tamron 18-270mm f/3.5-6.3
Canon 50mm f/1.8
That would get you capabilities to shoot everything from 11-270 (with the Tokina & Tamron), as well as some low light capability with the Canon 50mm f/1.8. You could even probably shoot nearly everything with just the Tamron 18-270mm, if you were willing to compromise some on image quality and/or miss a few photos in certain scenarios. If you need wider than 18mm on a crop, you could take multiple pictures & stitch, as previously suggested.
Also, worth considering is that sometimes the most interesting part of a vista is actually more in the general purpose or even telephoto range. Consider the case of a sunset: if you take that photo with a UWA lens, the setting sun is going to be a tiny element in the picture, whereas if you use a telephoto lens, you can make the setting sun a major element of the picture.
Ultimately, it depends on what balance of convenience vs. cost vs. image quality one is willing to tolerate.
Also, not relevant to the original question but relevant in the grand scheme of things, I think the Canon 60D is a great choice for performance vs. value. Much cheaper than a 7D, but has the same sensor, the majority of the better controls, and a swiveling screen which can be handy for video or unusual photo situations. However, the 60D is also not much more expensive than a T2i or T3i, but has significant advantages i.e. better hand holding size (not too cramped), better controls for better access to features, extra info LCD on top (in addition to main LCD), better battery life, better quality (listen to the shutter sound of a 60D vs. a T2i - the 60D shutter makes a solid clunk, the T2i shutter makes a a high-pitched wheezing sound, better weather sealing etc.)