Any suggestions? I don't like the top jungle Jarvan guide on Mobafire too much. Warmog's and Phage are definitely good items on Jarvan. Hexdrinker is also good if you need MR. Not sure if going Trinity or Frozen Mallet is better though.

Trinity almost always, unless you're dying too much. It's no longer a core item, though.
Jarvan doesn't really have a set build, but my "preferred core" (if it's viable, I will buy it over other items) is:
Cleaver/Banshees/Treads or Tabi/Triforce/Randuins

J4 carried me out of 700 ELO

Don't use mobafire ever.

http://www.solomid.net/guides.php?g=21480
http://www.lolpro.com/guides/jarvan-...gle-by-crumbzz

Get a spirit stone and then 4 warmogs and boots.
i'm from mobafire trust me

I just go for a few ad like Trinity Force black cleaver and then i go for warmogs guardian and my boots and maybe some more ad. This build has worked for me but im a lvl 14 newbie. I've found its better to make your own builds because then you will know how to use them rather than going off of someone else.

i start off machete and 5 pots. i usually farm the jungle/gank until i have at least 1k gold and when i b, i buy madreds and ruby crystal. if i got ****ed up before i have 1k gold i just finish madreds and get boots if possible. then i just keep farming/ganking and i finish warmogs. then finish boots or if you want damage get brutalizer. if you need more tankiness get the ruby crystal before long sword or just build a phage before brutalizer. after that get whichever one you didnt before. farm/gank etc finish bc and frozen mallet.

end game core build should be boots, warmogs, bc, frozen mallet. the last 2 items are situational. if the enemy team is heavy ad i get randuins and sunfire. if the enemy is heavy ap i get a maw and last item is whatever the hell you want.

look at my match history if you want a visual of my build.