I think you should consider either a Swiss Lace base or probably better still, a V looped ultra thin skin.
Both of these would allow you to expose the hairline.
The skin base is quite delicate, but easier to clean up.
They're not hot in themselves to wear, but sweat can build up under them so you'd need to detach at least weekly.

A lot of people don't like the V looping, but honestly unless you're on top of it with a magnifying lens, it really can look very realistic.
The V looping also helps keep the hair 'buoyant' which will be ideal for spiking.

You can use NX GEN white glue from Hair Direct or Oil Resistant White Glue available through ebay.