Honestly, I would look for other players to run Heroics 2/4 but you got lots of variables to consider. I got one of each class overleveling you by a couple of notches.
First off, you got to look at your build and gear. Are you dps, tank, hybrid for survivability? You want to solo those, you gonna get hit a lot and hard. Are you propped up gear wise?
If you want to do Heroics 2/4, Marauders could do some, if not all. Just be prepared to possibly die...And maybe scream out in frustration. But hey, it could be a fun challenge.
I would just do SOME of those Heroics and Flashpoints when my marauder OVER levels them. I did and was not as facepalming a challenge as the ones at my level. That's probably due to my gear being subpar though and the fact I have yet to master this AC.
Juggs and sins will do better (again, depends on build/gear). Can still be a challenge but I feel they are less so than marauders. I solo'ed some Heroics 2 on both jugg and sin (with my Jugg being better geared) and had less trouble with my jugg. Not saying a sin can't solo those Heroics.
I'm also leaving your experience and player' skills out of this.