Not to argue with Prideful, but on my second character (Caldari) I skipped cruiser and went directly for Drake. A lot of skills between the Caracal and Drake overlapped. The Drake is ridiculous in that you don't need a lot of SPs to do all of the lvl 3 missions (provided you know what you're doing in missions).
Minimum skill for Drake, plus heavy missiles, Energy Grid Upgrade (for shield relays), Shield Upgrade (for shield rechargers and extenders), and Tactical Shield Manipulation (for active hardener) takes 4-7 days depending on skills. Then, you can train drones on top of that. With that, you should be ok for everything but Blockade. The once you train tech 2s, you can do Blockade w/o issues.
Whatever you do, DON'T POST YOUR DRAKE LOADOUT. (: Of course the OP is asking about lvl 4s, but I couldn't let Prideful's comment go. d: