I don't think I have a steady enough hand to paint the stripes, but if I did, acrylic would be the way I'd do it.
I have actually used the kit decals before. The old "pro modeler" '69 Charger had them. I remember they were a pain to apply because they tended to break, but they looked OK in the end. I was about 14-15 when I tried those last, so if I could get them decent looking then, they can't be that difficult to apply with a little patience.
Also, if you don't touch them, they'll stick just fine, but if you want to clear coat them once they're on the tire, stick to using an acrylic paint and you should be fine.