I am getting back into photography and would like some advice on a few lenses. I am going to purchase two lenses to cover up to at least 28-200mm. My price range is < $1000 combined. I am thinking for the lower range either a Canon 28-105 3.5-4.5 USM or a Sigma 28-70 2.8 EX DF. For the upper range either a Canon 70-200mm 4.0L or a Sigma 70-200mm 2.8 EX HSM IF APO. Any other's are welcome provided they don't cost an obscene amount. Ideally I'd love to get 70-200 2.8L IS and a 24-70 2.8L but I am in college and not rich. Thanks for any help.

Carson