I agree with Effenhoog on pretty much all points. I'd imagine Wave 3 as follows:
B-Wing 3 attack 1 defense 4 hull 4 shield
abilities: target lock, focus, barrel roll (they can rotate around the cockpit, and it would open up a lot of options for gameplay)
upgrades: torpedo torpedo ion cannon (non turret)
Pilots: Keyan Farlander, Ten Numb, Nova Squadron, Blue Squadron
Z-95 2 attack 2 defense 3 hull 1 shield
abilities: target lock, focus, evade
upgrades: missile
Pilots: Colonel Cracken, Mara Jade (smuggler), Tala squadron, Mercenary pilot (smuggler)
Tie Bomber 2 attack 1 defense 4 hull
abilities: target lock, focus
upgrades: torpedo torpedo missile mine
Pilots: Major Rymer, Captain Jonus, Scimitar Squadron, Beta Squadron
Tie Defender 3 attack 3 defense 3 hull 3 shields
abilities: target lock, focus, evade, barrel roll, boost
upgrades: missile
Pilots: Colonel Jendon, Captain Yorr, Onyx Squadron, Advanced x7 prototype
Then I'd add some more upgrades:
Mag pulse warheads- missile, 1-3 2 attack. If it does at least 1 damage, that fighter may not roll attack dice this turn
Ion pulse Torpedo- torpedo, 2-3, proton torpedo stats but also adds ion counter if at least 1 damage done.
Countermeasures- modification, adds evade to actions
Jamming Beam- modification, if within range 2, may action to reduce one enemy attack dice by 1 this turn