I vote for new lenses over new body unless the 5diii is in your price range. Unless you are making loads of money at this, or need to shoot totally wide open, I would not bother with the 50 or 85L. the normal EF equivalents are more than adequate for most uses. Of your choices, I'd shy away from the sigma, that lens normally needs some AFMA, and I don't think the 5d classic has this feature (although I could be very wrong). So that leaves you the 50 1.4 which if you read lens rentals battle of the 50mm is a pretty fantastic lens for the price. I am a big fan of the 85 1.8 for it's performance and value, you do need to be careful not to shoot it wide open in high contrast situations or else you'll get purple halos at the transition points, however I generally live at f5.6 for portraiture so I don't see the purple fringing some complain of. Even if you do it's easily correctable in post and it's generally no longer a concern by f2.2 and smaller. The 135L is an animal, nothing quite like it out there, quick to focus, super sharp wide open, if you can afford it, get it. If money is a concern then get the 85 1.8 over 135 L, if not then the 85 1.8 and 135 L. If I had to only have 2, then it would probably be the 50 1.4 and 135L.