I also recommend that you seek out non-Canon prime lenses and adapter to fit on 600D. I shoot with 600Ds and I have been using Olympus 28mm (2. and 50mm (1.4). Glass that was made in the 1970s. Glass and metal lenses that are built to last. Resale shops, flea markets, and classified ads, like craigslist or other online sources. You might come across someone looking to dump a box of ancient lenses and cam bodies for little to nothing. Buy the whole thing and then grab those yummy primes from days gone by. I also have a 400mm Olympus lens that is literally 18 inches long. Ridiculous. It is for show only at this point, I have shot some photos but it is so unwieldy that is is best seen as a conversation piece only.
good luck dynazor
good luck dynazor