In my experience with my old car using LEDs you have to get a really good brand LED to get something that will be reliable. Really good brands cost money. I did the original full swap using all LEDs through superbrightleds and in about 2 years time I had basically replaced most all the LEDs I originally had. Most of the LED replacements out there, good quality or not, are not near as bright as the factory bulbs. I struggled with that issue in my tail lights and my front turn signals. The corner turn signals on my car were basically worthless. They barely put out any light. The main front turns even after I replaced them with brighter ones, never were as bright as the standard lights. The rears didn't light up the tails as well. And there really wasn't a lot of change in lighting between running lights and when you hit the brakes IMO. The things I did like about the LEDs were replacing the interior lighting with white light rather than having the warm yellow light of the standard bulbs, as well as white lighting for the license plate. Of course you have to get quality because my plate lights didn't take long to start flickering. I used the same bulbs for my dash panel lighting which also died quickly. I replaced the original interior lights because one died and the other was too dim. So all in all the only original LEDs I have in that car are the reverse lights, which are surprisingly bright compared to stock which is different than what I saw with most LEDs. All turn signals and tails are back to factory bulbs and working much better, brighter, and safer that way. I did enjoy the instant on off of the turn signals, it made for a nicer look for the car. But the drawbacks were too much for me.
So the moral of my story is get quality LEDs the first time around if you're going to bother with the swap. Personally I will be sticking with stock lighting with my Fiesta and from now on.
If you still want to go for it, VLEDs.com was my favorite place to get better quality stuff. I would skip superbrightleds.