tripod

Go to Adorama and B&H's websites. Just buy yourself a tripod head/leg combo that works for you, although your budget is a little low for the truly serious stuff. Read this enlightening article:
http://bythom.com/support.htm

Realistically, anything that is tall enough without the center column extended is also too large to carry. For example, the Manfrotto 190Xpro is a good travel tripod (as are the carbon versions, 190cxpro3 and the smaller-when-folded 190cxpro4), but you have to extend the center column to get higher. The 055 series are larger, but probably too big to carry.

Slik are supposedly good performance for the money, as well as velbon.

For a head, get yourself a ballhead. A T3i is light, so anything that is rated to more than 4 lbs will be sufficient for you. I have the Manfrotto 494RC2, and I like it. I'd recommend getting a quick-release tripod head, and once you choose a brand, run with it so that all plates and tripods are interchangeable. I just used Manfrotto because that's what my dad used, but Arca Swiss, Giottos, Gitzo, etc. are all just as good, if not better. The 494RC2 or similar would be good for you, but this is over half your budget already.