First of all, you used the word "small". That really doesn't apply to any of the L-series primes. Nor does the word "light".
Second, for approx. the same money you might get a 50L or an 85L.... Or you could get 28/1.8 and 50/1.4 and 85/1.8. They make a very nice trio on a crop sensor camera and are very good performers. They're faster focusing, a lot more compact and lighter weight than the L lenses. Not that the L's aren't lovely, big hunks of glass. They are very cool lenses I drool over and would love to display on a shelf, under glass. But from a practical standpoint, the three mid-grade lenses serve my shooting purposes much better. I guess I'm just not an L-coholic 
50D to 5D Classic? Nope... unless you are willing to give up Micro Adjust, much faster AF and some other nice features that the 50D offers. The biggest single feature 50D offers that 5DC doesn't is likely Sensor Cleaning... With primes you will likely be changing lenses even more frequently and the 5DC is a real dust magnet. But, your lens kit (nothing wider than 17mm, except for a FE you describe as "junk") and your avatar image suggest you are a sports shooter too... a specialty where the 50D is a solid performer thanks to it's faster handling and quick AF, and either of the 5D's are less than stellar. (Before someone flames this statement... yes, you can shoot sports with a 5D.... but you will have far more keepers with 50D, 7D or one of the 1D series, primarily thanks to faster and better tracking AF).
Full frame and bigger aperture primes are ideal for portraiture, weddings, and such. If that was your largely exclusive area of work, or the one that pays the bills, then a full framer would be the way to go. But are you looking to completely recommit to just this specialty, or do you plan to keep shooting other stuff, too? The 50D is more of an "all arounder", to include action shooting, than either of the 5D. That's all I'm really saying here. I'm not saying that the 5DC isn't a great camera... It is. The 5DII is even better. But, I'd suggest thinking of eventually adding a full frame camera to compliment your crop camera, if and when that makes sense.... not to replace the cropper. Using the two formats together with mostly EF lenses really leverages your kit for all it's worth. It's sort of like back in the good/bad old days of film, using a 35mm camera system complimented with a medium format rig... except with today's DSLRs the two formats can largely share the same kit of lenses (so long as they're not EF-S) and system accessories.
), and I think I want a small prime L. Ill likely sell my mk1 Nifty if I spring for the 50L or I thought even of saving a little monies and buying the 50mm 1.4. But I see the samples of the 85L's and some others and it leaves me in a predicament. This will be more geared toward wedding usage and portraits. Ive shot a couple of my friends kids lately (haha) and have been asked if Im interested in doing baby pictures and such. I used a 50L before and liked very very much, very sharp. I have never used any of the other smaller L primes. Not asking you guys what to buy, just looking for opinions and suggetions.
