Honestly, unless you have a line on these lenses used (or know somebody who found a case of them that "fell off a truck"), your $1000 budget isn't going to be nearly enough except for the 75-300 and an off-brand macro (several of which are very good) or the Sigma 24-70.

Given your subject matter, I wouldn't go for the 75-300. I'm not saying that it's a horrible lens, but if 50mm is your widest lens and your next choice is at 75mm at the wide end, you're missing a lot of territory. The 300mm end of the scale is equivalent to 480mm on a full-frame (or 35mm) camera, and that's too long for shooting people to their best advantage. (There are ways to make an extremely long "people" image work, but it usually involves making the person/people a subtext to another subject. Or celebrity peep shots, which have little to do with flattering your subject.) You would be much better off giving up what seems like a lot at the long end in order to get something considerably shorter at the wide end of the zoom range. If you want to go long, the Sigma 50-150mm f/2.8 and the Tokina/Pentax 50-135mm f/2.8 (if you can find one -- Tokina makes them for the Canon mount, but the supply chain seems to be broken at the moment) are the APS-C equivalent of the 70-200mm pro standbys. (Why Nikon and Canon don't offer a fast 50-135 baffles me.)

Of the choices you've offered, the Sigma 24-70mm comes closest to fitting most of your requirements. It falls within (or just ever so slightly beyond) your budget, and it offers an excellent range of focal lengths for shooting people and general travel photography. It isn't a true macro lens, but it does focus to 40cm and comes close to a 1:4 reproduction ratio at 70mm, which is sufficiently "macro" for florals on APS-C. 70mm, though, might be a little short for some types of wedding shots that are in vogue lately (don't worry -- we did just fine without supertelephotos at weddings in the caveman days, and I'm sure you can, too). The Canon 24-70 is similar, but it'll be tough to haul in that catch for under $1000.

To a point, getting physically closer beats getting optically closer every time, and a 70mm lens on a crop-sensor DSLR is a lot longer than the 110mm "long" lens I used to use on a 6x7cm medium-format camera for weddings. You might want to go longer later, but don't try to do it all with one lens unless you're willing to give up a lot in the bargain.