Its depends on what type of feel you want for your army...I play Flesh Tearers and have used both styles. Understand white gives you a vibrant look to your model, while black gives you a dark gloomy look to the model. You could try both and see which one is easier/cooler for you.
If you do black I would use the Mech Red, line in the recesses with watered down brown ink, high light w/blood red, highlight with blood red/orange mix(50/50). Then to top it off hit the model with a watered down red ink for a nice glaze finishing with a spray of dull coat.
As for white I think Bloodhound pretty much summed it up!!! God luck bro...