I'm working on something like this right now. Ever since my brother in his 7,000 lb Yukon flipped his truck after getting cut off by an idiot who said she never saw him, I've been trying to figure out a way to add Daytime Running Lights to mine.
I'd like to keep it stock looking. The idea that I have is to cut the harness to the front blinkers, wire them up to an ignition hot relay so they stay on. This relay would have a ground circuit interrupt to cut constant power with a turn signal input from the harness. It will require 2 relays as one relay will be the power circuit and the other to cut the ground circuit on a power input from the harness.
OR
take the easier way out and just put brighter LED 194 bulbs in front the marker lights and wire them up ignition hot.
Unless anyone else has an easier way to accomplish this. Opinions welcome..