OOT a bit, as I will be mostly doing portraiture thingy (outdoor), other than the 50 f1.2, which one should I choose between the 135f2 and 85 f1.2?Focal length for portrait very much depends on how tight you want to crop - head and shoulders, upper body, or whole body. So your best bet is to experiment and find out what you're most happy with.
Your crop camera, 50 and 85 will give you a good idea of what an 85L and 135L's focal lengths are like on FF. (your 50 acts like an 80, and your 85 acts like a 136) - so try them out, and then bear in mind how long you'll be using the lens on your crop camera before buying a 5D3.
The 85 is a middle ground between the 50 and 135, so its probably best not to get all three - you'll probably not end up carrying all three around, and even if you did, you'll no doubt not use all three in one session.
If you want to go with a 24 and 50, the 135 could be best. If you're happy with just two primes, 35 and 85 could be the way to go.