With Jarvan, you could go full 25 armor pen but I don't find it THAT strong unless he's jungling. Going with the bit of AD and the full offence provides him with a lot of dmg early.

armor yellows and mr per lvl blues are pretty standard for Jarvan.

I like full offence, gives me quite good dmg to dish out. the 9 in utility could also be put to use in defense I guess, if you want the extra armor and mr, both are very viable imo.

Flash/Ignite is what I prefer.

Flash/exhaust or ghost/exhaust or ignite is also fine.