Kha, Vi, and Fiddle I'm personally fine with, as well as Zac. If you want to do more damage, I'd suggest trying
, he's got some surprising damage with just Elder Lizard and a Brutalizer item, and he can still be the excellent tank your team will probably need. You can also try
for it, though from what I've played it takes a bit more items than Jarvan for Malphite to get to doing some damage.
Above all I'd stay away from Rengar and Hecarim personally, same goes with Nocturne. I may be wrong (as I can always be wrong), but it seems like with those three unless you get early kills and get your personal snowball rolling, you're gonna be kinda useless. Get killed early in the game and it sets you back very far. I've killed Rengars at level 5-6 and they just were never a threat from that point on. You can still use them, but be careful about their tendency to NEED to snowball.
I've also seen people have good success with
and
.