Drake can handle level 4's if you fit it right. The rigs are what make the drake excel, but there as much as the ship each.
Spent a lot of isk over the last few nights on my alt kitting out my Navy Raven (what else) with faction. Chews through missions real quick now, 650 DPS, tanks well, not that it matters if everything is dead. For those that are interested:
[Raven Navy Issue, New Setup 1]
Power Diagnostic System II
Power Diagnostic System II
Caldari Navy Ballistic Control System
Caldari Navy Ballistic Control System
Caldari Navy Ballistic Control System
Caldari Navy X-Large Shield Booster
Caldari Navy Shield Boost Amplifier
Ballistic Deflection Field II
Heat Dissipation Field II
Explosion Dampening Field II
Cap Recharger II
Caldari Navy Cruise Missile Launcher, Paradise Cruise Missile
Caldari Navy Cruise Missile Launcher, Paradise Cruise Missile
Caldari Navy Cruise Missile Launcher, Paradise Cruise Missile
Caldari Navy Cruise Missile Launcher, Paradise Cruise Missile
Caldari Navy Cruise Missile Launcher, Paradise Cruise Missile
Caldari Navy Cruise Missile Launcher, Paradise Cruise Missile
Caldari Navy Cruise Missile Launcher, Paradise Cruise Missile
[empty high slot]
Capacitor Control Circuit I
Capacitor Control Circuit I
Capacitor Control Circuit I
Hammerhead II x5
Hobgoblin II x5
Costs about 1billion total. No one gank me please
EDIT: Shield Hardeners are mission specific of course