Is jarvan IV a good top lane choice?

Yeah, Jarvan is definitely a strong solo laner. He has pretty good AD scaling with Q & R, and has good teamfight presence/ roaming ability. The only thing is, he's one of those champs that really needs to snowball to make a large game impact, because he does eventually get outscaled by other champs. I think a good solo build on him is:

With that build, you get nice and tanky, have good sustain, and do solid damage as well.

J4 does well top and beats a lot of champs. Not sure how he does against the ranged top cancer, but I'd guess he'd do better than many melees.

What about lee sin top?

I was wondering is Jarvan IV a good top laner to pick up.

He's not bad, if you can force engagements to be spread out enough his passive and ability damage is pretty brutal, and easily abused with a 1337 stick.

Main issue is working around his HP/mana sustain. He wins a lot of trades early due to his passive and burst, just want to spread them out enough so he's always got his passive and burst for each trade.

A lot of top-lane picks have HP sustain somewhere in their kit, and a decent number are manaless or have solid mana sustain - so sustain is generally J4's weakpoint.

Also - if you take him top, keep in mind he's a defensive champion that scales really well with defense and his potential team-fight contribution is heavily reliant on having solid defensive itemization.

J4 scales pretty well with offense for his archetype, but a lot of champions simply scale with offense much better than he does. You're not going to win an AD adventures battle against a Riven, Pantheon, or Fiora. You will win a tank-off with things like Sunfire Cape or Thornmail though.

For items, the other big thing to keep in mind is the average game is ~33 minutes long and 11,000 gold per champ. Toss in boots, wards, pots, and the fact you're probably going to have unspent gold at the end of the game what with a decisive teamfight and structure bounty, and you're looking at ~3 major 3,000 gold items for your build.

So, 2 major offense items on J4 before defense means that the tankiest J4 is getting with items is 1/3 tank at the very end of the game, and he'll be glass-cannon squish (outside of his shield) for a solid 67% of your average game.