As said above peppers like the balanced ferts, but for seedlings I always go with a 5-1-1 fish fertilizer at about 1/4th strength. I wait until they get their second or third set of leaves on them and start.
Once they grow up a bit, maybe 3 inches I start with a semi balanced fertilizer. My NPK fertilizer is close to balanced something like 5-4-5 I think and my micronutrients are all over the places, But Ca, Mg, Cu, and S are my really main micronutrients that seem to help the most.
Get your plants and a good schedule and they will be awesome for you. Get them on an unbalanced schedule of ferts and they may be a bit hotter but not as good of producers.