I personally love this build and have tried this, and have been very successful as an off-tank. If anything, you will do your best at solo top lane.

Runes are pretty basic for a tank, not an off-tank, but i include 9 glyphs and 3 quintessences for health mainly for the atmas(lol).

I use 0-21-09 mainly because of defense and also having a bit of health and health regen.

You will love these items. The beginning items are very great, and give you very good survivability in your lane, but watch out for your mana until you get your philosophers stone. I know that they are costly, and you will probably only get to randuins at most times, but it is a very good item build for off-tank jarvan.

For the skill sequence, I max out my E because it does great damage for harassing, AND another great thing is that it gives you more armor, as well as more attack speed. I know that people would think that Q would be better to max out first because it does more damage and it costs less mana, but E just has such a great passive as well as a great harassing ability(and i really only use it for it's knock-up ability when used with his E), I would personally max his Q second. Lastly is his W, it is a great ability for off-tanks, but you already have stopper abilities such as his E+Q and his R, that you will most likely get the kill AS LONG AS YOU ARE WITH ANOTHER PERSON. You will not always get the kill if you are by urself, so if you can, go with a carry and make sure to support them the whole time with your E+Q and R.

Flash is good even though i already have E+Q, because jarvan must have both abilities used in E+Q in able to use it, and you will have 2 abilities in able to escape, or get a determined kill.

All-in-all, jarvan is great solo-top, and even in a duo lane. Please get back to me what you liked or didn't like about this build, and I will try my best to fix it. Thanks!