You need the legendary cloak to fight Ordos, until 6.0. If you don't have it, then it'll be easy to kill him once 6.0 hit.
As for Garrosh normal, you need to hurry. The achieve is available only until 6.0 hits, which should be in 1-2 weeks (3 at most). I wouldn't mind stepping in and helping a guildie get his mount if I'm available whenever enough people want to run it.
EDIT: As for heroic, it is highly unlikely that you would be able to run it at that ilvl, as the 25 man is on break and the 10 man is pushing to try for a Heroic Garrosh kill before 6.0.