Canon 5dMII all-purpose lens

sotirius wrote:

Dear forum readers,

I just upgraded my Canon d450 to a 5d M2(couldn't justify the price of the M3 and the new M2 was just 1800$). Anyway, I purchased the body only with no kit lens. The reason i did this is because i want an all-rounder f/2.8 lens. As i would like to shoot shoot two weddings for my relatives, the f/4 would have been too dark for church and low light use. My budget is up to 1500$ for one lens, and one or two other cheaper lenses. I have a saving of 2200-2500$ in total. The first 24-70 f/2.8 lens that comes up on my mind is the new Tamron. I read on lensrentals they say it optically beats the Canon and Nikon 24-70 and it has in it's favour a built in VC. The focus speed is just a notch slower, or same as the other lenses depending on the camera body. What would you guys say? I've also heard some bad reviews about Tamron, saying they are not built to last, but as this is a new lens maybe it's a different story? Is there any other lens in this zoom and price range you can recommend me? I would also like your opinion on the Canon 50mm f1.4 Would this be a good choice if i buy a f/2.8 24-70, because i would have the 50mm focal length covered at with a fast f/2.8.

And finally, for a zoom lens i was looking at the Sigma 70-200 2.8 OS, sold for 1000-1200$. I know I can get the Canon 70-200 f/4 IS for the same price or the Canon f/2.8 with no IS, but I don't know what to do. What's your say about this Sigma lens? I don't really like f/4 as I said before, so would the Canon f/2.8 be any good with no stabilisation, or should I give the Sigma a try? Any other lens you can recommend? Sorry for asking so much but I've just got my first FF camera, and I really don't know how do these lenses behave on FF. So far I have made a bad investment in DX format lenses, and I can't use any of them on my new camera.
Thank you all for your opinion, I would love to hear your say.

p.s. is there any kind of adapter or converter to use DX lenses on a FF Canon body? I know Nikon FF bodies take DX lenses with no adapters.