I skipped to the "perfect team" after I read "Sona-Great heals" Ohh my God
Sona gives you extra ad/ap and also harasses giving you this boost
Her heal gives you extra armor and mr (I think for a little amount of time)
Gives you a speed boost that'll help you run away from or chase any enemy champions
And then you miss this all might ult from her??? Her global fucking stun???
Bro you're going to have to get more info on all of the champs in the game if you're going to make a list like this.
And you're perfect team can get owned so hard.
By a team composition of
ADC - Ezreal (his e will counter jayce's melee atks since his ranged damage sucks)
Support - Sona/Blitz (Sona has the heals and harass and stun, blitz has a pull that'll dominate early game and thus dominate late game)
Mid - Kat (counters morgana hard and will render her useless)
Top - Rumble/Vlad (AP will own malphite top pretty much, plus they have aoe-ish ults that'll help from this team composition)
Jungle - Amumu (Bandage toss will give great ganks, e does lots of damage if you max it first, and his ult is an absolute game changer)
With the team composition like this, you just have amumu ult, then kat goes in and ults, then sona ults with Rumble or vlad, Then an Ezreal ult and they're all dead. Plus, if both teams are at the same level of skill, your team would've gotten countered hard early game and they'll melt even faster.
Ragin like a boss
Edit: Just read your "mid champion" section. Ryze, Diana, Morde, Cho, Swain, and Elise not tanky enough for you???