You're busting balls here Monkey Whatever you decide to do is up to you, but if you're serious about doing weddings...I wouldn't vote for the lenses you opt for.
My advice: Buy whatever camera you like(camera is less important than a lens for quality images) and combine that with good quality (cheap/within budget)lenses.
For wedding the Tamron 17-50 F2.8 is a very nice(if not the best option in your budget) lens to start with. It will be able to do 75% of the important shots easily(example number, because it relies on different factors: weather, inside/outside, lighting etc). The other percentage would be low-light shots. Therefor I would pick a fast prime. The 50mm f1.8 is a good start. The 50mm f1.4 or 85mm f1.8 are also good valued lenses. With that combo you could meet the pro-grade levels of image quality in a payable package.

If this is not an option, you should seriously consider renting. Yes it does cost money, but it's only a fraction of the price you'd pay to own the best lenses. In weddings, you could easily calculate these costs in the price. And you'll be able to save for better equipment fast if jobs go well.

Bottom line, a lens with an f5.6 max aperture and a lowly build/quality will not likely give you good results. Well perhaps if you're only doing all outdoor weddings on a sunny island you've got some chances. The (cheap) photographer on my sisters wedding was limited by an f5.6 lens and it definitely shows in the results. These days you'd post that stuff and your opinion about the photographer on facebook and BOOM half of the chances for new jobs fly out of the window if the message is bad.
Be smart about this. If you're truly serious about wedding-photography, don't push your boat out too soon and really consider your options. Making good photos isn't hard, but making a living out of it definitely is.

I'm not saying it's impossible to make good shots with the lenses you mentioned, but you'll never get as good results(lens-constraints) as with the better made lenses. Also an experienced photographer will have less trouble dealing with gear-limits than a starting fresh amateur.