you lack a drago resist, so a steel type is suggested for the last slot if u plan to use that. pick one or two to be the focus, or a few to be the core that the team will depend on to succeed.
you should choose a lead that either attacks, sets up utility stuff like stealth rock, or sets up weather. infernape makes a great attacking lead, starmie too but wih rapid spin. gliscor is good for taunt and sr. other leads to consider are machamp, roserade, etc u can see the smogon sets.
with heatran and tyranitar gone bc of no legendaries, the metagame for u and ur friend opens up. heatran threatens steel types like scizor, and grass types. tyranitar gone means less likelihood of sandstorm and no pursuit, making ghost types, especially gengar, much more effective. even starmie can work much better now.
a set up sweeper is always nice for late game, SD lucario or SD/NP nape or SD heracross should all work for you, DD gyarados + that electivire is good, since you can get some free motor drive boosts for vire. infernape can be a mixed wallbreaker, while heracross can help wih that by using raw power instead of super effectiveness. in that case, roserade would make a nice lead while you get another mon to set up stealth rock.
hope that helped :)