I know I need a load resistor for them, but do I need one for each bulb or do I need to get one and install it right after the signal fuse?

 

You need to add a resistor on each bulb circuit, putting it after the fuse would not put a load on the right circuits. If your feeling cheap no problem using a regular incandescent bulb instead of one of those big ol resistors. But of course that wouldn't be the best way, the bulbs will burn out with time, and if not done right it can look like sh*t. A load resistor should never fail, and when that bulb does go out so will the LEDs, until you replace it.

 

What if I left the regulard bulbs in the back, swapped the LEDs over to the reverse light socket, and only had LEDs in the front bumper signals. By only putting two resistors up in front with the two LEDs will everything run smoothly?