You could try a sign shop, like fast signs or something. Have them make a decal with the text you want.
if you want it painted on you could have an inverted decal made, like a rectangular piece with the text cut out of it. Lay that down for a stencil and paint over it, then peel the decal back off.
Or another option, just have the normal text decal made and put it on the hood where you want it first. Then paint the hood flat/matte black. Then peel the decal off and your text color will match the rest of the jeep.
Decal isn't the cheapest way to go, but it will probably give you the best finish.
You could try laying down painters tape, and using an exacto knife to cut out your design. But you run the risk of cutting to deep and cutting into your paint.
Alternately you could try making a stencil out of cardboard or signboard or something. But you will end up with overspray because it won't stay perfectly tight to the surface. So your lines will end up fuzzy and not clean looking.