When I got my 4xinnovations bumper I had some LED's for turn signals, they just were not bright enough and they blinked too fast. I know I can buy a resistor to get them to blink at the correct rate, but then they are still not bright enough and I hear the resistors get HOT (just a blinker I wasn't too worried about that aspect).
I decided to move my blinkers to my side markers, cut some wires and realized that my side marker lights were still blinking fast. The bulb isn't big enough so I grab one out of my buddies Audi trunk light and it worked great. Unfortunately, it did not have any info on the bulb so I stop by Advanced and get the same size bulb (same physical size, not same watts and such) and it still blinks fast. Now I run out to another auto parts store and get what I think is going to be the correct one(916's) and I see some no name light with no info, but it's yellow and only 3 bucks so I grab it. Get back and son of a gun it still blinks fast, throw in the cheapo's and all is good. Oh yhea, I also disabled my DRL's.
As far as getting them both to work I don't see that being a issue. I assume you just need to tap off you original turnsignal wires and connect them to the side markers. Not sure if you will have to upgrade the bulbs like I did or not. If you do need to upgrade get yellow bulbs that are 921's (I think), not 916's.
Let me know if it works for you.